Reorganized project.

Everything is now in a namespace under a GDCC namespace.
Interface headers are now stored separately from the source.
When headers include other headers, it must always be by a relative path.
Relative paths should always go via the include root. That is, prefixed with .. even when including a header in the same directory.
AST: Statements should be passed/stored by pointer-to-const.
CPP: Moved Core::TrigraphBuf to here.

Trigraphs should not be needed by any other language, so their handling should not be in Core.
CPP: Replaced the IStream::NeedHeader static with a non-static member.

Replaced CPP::IStream::NeedHeader with a non-static member that CPP::IncludeDTBuf accesses via a reference passed to its constructor.
AST: Rewrote Type_Size to defer to Bytecode for sizes.
CC: Initial work on Scope class.

Also added basic AST::Attribute, AST::Function, AST::Object, and AST::Space.
Fix build with clang 3.4
Core: Do not pass __VA_ARGS__ to GDCC_Core_StringList macro.

Added -Wpedantic which led me to discover that the string table must not generate __VA_ARGS__ with its macro, due to low-level super-powers of the identifier.
Core: Fixed ParseRatioC error.

Fixed blatant stupidity in Core::ParseRatioC which checked the "sign" of in rather than valE.
IR: Fixed minor stylistic mistake.
GDCC: Fixes to compile in gcc.

Use () instead of {} for initializers of reference members in order to please gcc.
Similarly, explicitly convert CounterRefs to pointers in some bool ? nullptr : CounterRef expressions.
GDCC: Addressed some gcc warnings.
Bytecode: Added generic put functions to Info.

Their behavior mimics the other function sets, setting relevant members and calling a virtual.
Also addressed some gcc -Wshadow warnings.
CC: Added initial declaration-specifier parsing.
CC: Added implementations for types.
Option: Rewrote option processing library.

Primary goal was to allow for multiple option lists in a single program.
Also wanted to remove partially implemented templates and generally clean things up.
CC: Added declarator and attribute parsing.
CC: Added specifier-qualifier-list parsing.
IR: Moved CallType and ScriptType to their own files.
Core: Removed all references to IR.