Use pedantic warnings

From the gcc manual:
Issue all the warnings demanded by strict ISO C and ISO C++; reject all programs that use forbidden extensions, and some other programs that do not follow ISO C and ISO C++. For ISO C, follows the version of the ISO C standard specified by any -std option used.

Note: ISO C++98 doesn't support the "long long" data type, so we disable that warning
-Winit-self can be removed as it's enabled by -Wall

CMakeLists.txt

@@ -32,7 +32,7 @@ else (MSVC)
     set(CPPLINT_ARG_OUTPUT      "--output=eclipse")
     set(CPPCHECK_ARG_TEMPLATE   "--template=gcc")
     # Useful compile flags and extra warnings 
-    add_compile_options(-fstack-protector -Wall -Wextra -Winit-self -Wswitch-enum -Wshadow -Winline)
+    add_compile_options(-fstack-protector -Wall -Wextra -Wpedantic -Wno-long-long -Wswitch-enum -Wshadow -Winline)
     if (CMAKE_COMPILER_IS_GNUCXX)
         # GCC flags
         if (SQLITECPP_USE_GCOV AND CMAKE_COMPILER_IS_GNUCXX)