Rename *BuildableConfig* to *BuildableModeConfig* to better name what it is
Add buildable models configuration files
Replace the huge hardcoded list for buildings

* Now it uses files in the config/builables/*.attr.cfg format
* I had to make huge constant arrays to avoid dynamic allocation
Remove unused defines in unvanquished.h
Init buildable attributes in every VM
Add config for the buildable attributes
Change some attributes to be more explicit
whitespace fix
Do not expose the classname for buildable configuration
Move ome parsers of bg_misc.c to their own file

* The new file is bg_parse.c
* It has some macros to make the parsers a bit less verbose
* Add a BG_ReadWholeFile function in parse.c
Add strdup to bg_lib
Allocate dynamic strings and do not break on error
Do not use an error code

* Parsing of these files should never fail unless in dev
* Clean stuff
 Rename *ClassConfig* to *ClassModelConfig* to better name it
Move BG_ParseClassModelFile to bg_parse.c
Move class.cfg to class.model.cfg
Move class.cfg to class.model.cfg
Allow the spectator model to use null fields
WIP: Implement the parser for class attributes
Add the classes attributes files