Feature/promote rollup logger visibilities (#585)

* promote RollupLogger's virtual methods & inner interface to global.
This should allow subscribers of the managed package to write their own plugins.

* added missing method to the interface laid out in the readme

README.md

@@ -980,6 +980,7 @@ public class RollupLogger {
     void log(String logString, System.LoggingLevel logLevel);
     void log(String logString, Object logObject, System.LoggingLevel logLevel);
     void save();
+    ILogger updateRollupControl(RollupControl__mdt control);
   }
 }
 

rollup/core/classes/RollupLogger.cls

@@ -23,10 +23,10 @@ global without sharing virtual class RollupLogger implements ILogger {
     private set;
   }
 
-  public interface ToStringObject {
+  global interface ToStringObject {
   }
 
-  public interface ILogger {
+  global interface ILogger {
     void log(String logString, System.LoggingLevel logLevel);
     void log(String logString, Object logObject, System.LoggingLevel logLevel);
     void save();
@@ -37,13 +37,13 @@ global without sharing virtual class RollupLogger implements ILogger {
     this.log(logString, null, logLevel);
   }
 
-  public virtual void log(String logString, Object logObject, System.LoggingLevel logLevel) {
+  global virtual void log(String logString, Object logObject, System.LoggingLevel logLevel) {
     if (logLevel.ordinal() >= this.currentLoggingLevel.ordinal()) {
       this.innerLog(logString, logObject, logLevel);
     }
   }
 
-  public virtual void save() {
+  global virtual void save() {
     // this is a no-op by default; sub-classes can opt in if they need to perform DML
   }