Add repo specific errors

1. Add Internal.errors.yaml to define repo specific errors
2. Update configure.ac and Makefile.am to generate code from error yamls
3. Add elog-gen.hpp generated by elog-gen.py

Change-Id: I6858f2c9f3c2100ce106d1effe7ad3f340117fec
Signed-off-by: Lei YU <mine260309@gmail.com>
diff --git a/configure.ac b/configure.ac
index 7a2ee4e..aa54962 100644
--- a/configure.ac
+++ b/configure.ac
@@ -47,6 +47,10 @@
     AC_SUBST([OESDK_TESTCASE_FLAGS], [$testcase_flags])
 )
 
+# Check for sdbus++ tool
+AC_PATH_PROG([SDBUSPLUSPLUS], [sdbus++])
+AS_IF([test "x$SDBUSPLUSPLUS" == "x"], AC_MSG_ERROR([Cannot find sdbus++]))
+
 # Checks for typedefs, structures, and compiler characteristics.
 AX_CXX_COMPILE_STDCXX_14([noext])
 AX_APPEND_COMPILE_FLAGS([-fpic -Wall -Werror], [CXXFLAGS])