Replacement of sccp_enum_macro.h. Cleaner implementation of the generated code (Requiring / Returning an enum type instead of an int. When misused the compiler will return a explicit warning about implicit conversion between enums). It also includes a method to lookup an string back to the enum value (even if the enum is sparse in nature). The str2enum lookup will be used to replace some of the config_parsers to base the on generated source code instead (in the near future).

git-svn-id: https://svn.code.sf.net/p/chan-sccp-b/code/trunk@5466 43c1dc8c-776e-4df2-8ef1-6e829299be21