Improve log collection API:

 - Allow setting a prefix for the log collection filenames
 - Allow defining the max file size of the log collection files

coreapi/linphonecore.h

@@ -1786,6 +1786,13 @@ typedef enum _LinphoneLogCollectionState {
 	LinphoneLogCollectionEnabledWithoutPreviousLogHandler
 } LinphoneLogCollectionState;
 
+/**
+ * Tells whether the linphone core log collection is enabled.
+ * @ingroup misc
+ * @returns The state of the linphone core log collection.
+ */
+LINPHONE_PUBLIC LinphoneLogCollectionState linphone_core_log_collection_enabled(void);
+
 /**
  * Enable the linphone core log collection to upload logs on a server.
  * @ingroup misc
@@ -1793,6 +1800,13 @@ typedef enum _LinphoneLogCollectionState {
  */
 LINPHONE_PUBLIC void linphone_core_enable_log_collection(LinphoneLogCollectionState state);
 
+/**
+ * Get the path where the log files will be written for log collection.
+ * @ingroup misc
+ * @returns The path where the log files will be written.
+ */
+LINPHONE_PUBLIC const char * linphone_core_get_log_collection_path(void);
+
 /**
  * Set the path where the log files will be written for log collection.
  * @ingroup misc
@@ -1800,6 +1814,34 @@ LINPHONE_PUBLIC void linphone_core_enable_log_collection(LinphoneLogCollectionSt
  */
 LINPHONE_PUBLIC void linphone_core_set_log_collection_path(const char *path);
 
+/**
+ * Get the prefix of the filenames that will be used for log collection.
+ * @ingroup misc
+ * @returns The prefix of the filenames used for log collection.
+ */
+LINPHONE_PUBLIC const char * linphone_core_get_log_collection_prefix(void);
+
+/**
+ * Set the prefix of the filenames that will be used for log collection.
+ * @ingroup misc
+ * @param[in] prefix The prefix to use for the filenames for log collection.
+ */
+LINPHONE_PUBLIC void linphone_core_set_log_collection_prefix(const char *prefix);
+
+/**
+ * Get the max file size in bytes of the files used for log collection.
+ * @ingroup misc
+ * @returns The max file size in bytes of the files used for log collection.
+ */
+LINPHONE_PUBLIC int linphone_core_get_log_collection_max_file_size(void);
+
+/**
+ * Set the max file size in bytes of the files used for log collection.
+ * @ingroup misc
+ * @param[in] size The max file size in bytes of the files used for log collection.
+ */
+LINPHONE_PUBLIC void linphone_core_set_log_collection_max_file_size(int size);
+
 /**
  * Set the url of the server where to upload the collected log files.
  * @ingroup misc