Fix nasa#711, Relative paths, typos, better dependency

MISSION_CORE_MODULES now set early (mission_build.cmake) allowing
override or append in user config.

Fixed typos in cfe_msg.h, and moved local to module until
APIs are cleaned up (still available as include)

Moving towards a module file structure

fsw/cfe-core/src/msg/CMakeLists.txt

@@ -14,9 +14,13 @@
 ##################################################################
 
 # Add the basic set of files which are always built
-set(CFE_ALL_MODULE_SRCS ${CFE_ALL_MODULE_SRCS}
-    ${CMAKE_CURRENT_SOURCE_DIR}/cfe_msg_checksum.c
-    ${CMAKE_CURRENT_SOURCE_DIR}/cfe_msg_fc.c
-    ${CMAKE_CURRENT_SOURCE_DIR}/cfe_msg_time.c
-    PARENT_SCOPE
+set(MODULE_SRCS
+    src/cfe_msg_checksum.c
+    src/cfe_msg_fc.c
+    src/cfe_msg_time.c
 )
+
+add_library(${MODULE_NAME} STATIC ${MODULE_SRCS})
+
+# Add to includes for header dependency resolution across modules
+target_include_directories(${MODULE_NAME} PUBLIC inc)

fsw/cfe-core/src/inc/cfe_msg.h → fsw/cfe-core/src/msg/inc/cfe_msg.h

@@ -105,7 +105,7 @@ void CFE_MSG_GenerateChecksum(CFE_SB_MsgPtr_t MsgPtr);
 bool CFE_MSG_ValidateChecksum(CFE_SB_MsgPtr_t MsgPtr);
 /**@}*/
 
-/** @defgropu CFEAPIMSGCmdCode cFE Message Command Code APIs
+/** @defgroup CFEAPIMSGCmdCode cFE Message Command Code APIs
  * @{
  */
 
@@ -158,7 +158,7 @@ uint16 CFE_MSG_GetCmdCode(CFE_SB_MsgPtr_t MsgPtr);
 
 /**@}*/
 
-/** @defgropu CFEAPIMSGTime cFE Message Time APIs
+/** @defgroup CFEAPIMSGTime cFE Message Time APIs
  * @{
  */