Organize headers in C-Extension

Header files should only contain includes that are necessary for the
compiler to understand the header. Includes needed by the implementation
should be included by the corresponding source.

With this philosophy in mind the includes in all c files were
reorganized.
As part of this reorganization the header `cmontecarlo1.h` was removed
and it's declaration moved to `cmontecarlo.h`

Resolves: #489

tardis/montecarlo/src/cmontecarlo.c

@@ -1,12 +1,16 @@
-#define _POSIX_C_SOURCE 1
 
 #include <inttypes.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <math.h>
 #ifdef WITHOPENMP
 #include <omp.h>
 #endif
+#include "io.h"
 #include "abbrev.h"
+#include "status.h"
+#include "rpacket.h"
 #include "cmontecarlo.h"
-#include "io.h"
 
 
 /** Look for a place to insert a value in an inversely sorted float array.
@@ -18,7 +22,7 @@
  *
  * @return index of the next boundary to the left
  */
-static tardis_error_t
+tardis_error_t
 reverse_binary_search (const double *x, double x_insert,
                        int64_t imin, int64_t imax, int64_t * result)
 {
@@ -59,6 +63,14 @@ reverse_binary_search (const double *x, double x_insert,
   return ret_val;
 }
 
+/** Insert a value in to an array of line frequencies
+ *
+ * @param nu array of line frequencies
+ * @param nu_insert value of nu key
+ * @param number_of_lines number of lines in the line list
+ *
+ * @return index of the next line ot the red. If the key value is redder than the reddest line returns number_of_lines.
+ */
 tardis_error_t
 line_search (const double *nu, double nu_insert, int64_t number_of_lines,
              int64_t * result)

tardis/montecarlo/src/cmontecarlo.h

@@ -1,29 +1,31 @@
 #ifndef TARDIS_CMONTECARLO_H
 #define TARDIS_CMONTECARLO_H
 
-#include <stdio.h>
-#include <stdbool.h>
 #include <stdint.h>
-#include <string.h>
-#include <stdlib.h>
-#include <math.h>
 #include "randomkit/randomkit.h"
 #include "rpacket.h"
 #include "status.h"
-#include "cmontecarlo1.h"
+#include "storage.h"
 
 #ifdef WITH_VPACKET_LOGGING
 #define LOG_VPACKETS 1
 #else
 #define LOG_VPACKETS 0
 #endif
 
-typedef void (*montecarlo_event_handler_t) (rpacket_t * packet,
-                                            storage_model_t * storage,
+typedef void (*montecarlo_event_handler_t) (rpacket_t *packet,
+                                            storage_model_t *storage,
                                             double distance, rk_state *mt_state);
 
 void initialize_random_kit (unsigned long seed);
 
+tardis_error_t line_search (const double *nu, double nu_insert,
+                            int64_t number_of_lines, int64_t * result);
+
+tardis_error_t
+reverse_binary_search (const double *x, double x_insert,
+                       int64_t imin, int64_t imax, int64_t * result);
+
 double rpacket_doppler_factor(const rpacket_t *packet, const storage_model_t *storage);
 
 /** Calculate the distance to shell boundary.
@@ -55,7 +57,7 @@ tardis_error_t compute_distance2line (const rpacket_t * packet,
  *
  * sets distance to the next continuum event (in centimeters) in packet rpacket structure
  */
-void compute_distance2continuum (rpacket_t * packet, storage_model_t * storage);
+void compute_distance2continuum (rpacket_t *packet, storage_model_t *storage);
 
 int64_t macro_atom (const rpacket_t * packet, const storage_model_t * storage, rk_state *mt_state);
 

tardis/montecarlo/src/io.h

@@ -1,6 +1,8 @@
+#define _POSIX_C_SOURCE 1
+
+#include <unistd.h>
 #include <inttypes.h>
 #include <stdio.h>
-#include <unistd.h>
 
 #define STATUS_FORMAT "\r\033[2K\t[%" PRId64 "%%] Packets(finished/total): %" PRId64 "/%" PRId64
 

tardis/montecarlo/src/rpacket.c

@@ -1,6 +1,11 @@
+#include <stdbool.h>
+#include <stdint.h>
 #include "rpacket.h"
 #include "storage.h"
 
+extern tardis_error_t line_search (const double *nu, double nu_insert,
+                            int64_t number_of_lines, int64_t * result);
+
 tardis_error_t
 rpacket_init (rpacket_t * packet, storage_model_t * storage, int packet_index,
               int virtual_packet_flag)

tardis/montecarlo/src/rpacket.h

@@ -1,16 +1,12 @@
 #ifndef TARDIS_RPACKET_H
 #define TARDIS_RPACKET_H
 
-#include <stdio.h>
+#include <math.h>
 #include <stdbool.h>
 #include <stdint.h>
-#include <string.h>
-#include <stdlib.h>
-#include <math.h>
 #include "randomkit/randomkit.h"
 #include "status.h"
 #include "storage.h"
-#include "cmontecarlo1.h"
 
 #define MISS_DISTANCE 1e99
 #define C 29979245800.0

tardis/montecarlo/src/storage.h

@@ -1,12 +1,9 @@
 #ifndef TARDIS_STORAGE_H
 #define TARDIS_STORAGE_H
 
-#include <stdio.h>
-#include <stdbool.h>
 #include <stdint.h>
-#include <string.h>
-#include <stdlib.h>
-#include <math.h>
+
+#include "status.h"
 
 typedef struct StorageModel
 {