For test of incremental build, ensure that recompiled sources will result in object file with different number of bytes.
Renamed 'Linker' to 'Archiver' for static library construction
- ArStaticLibraryLinker -> ArStaticLibraryArchiver
- Separated archiver spec from linker spec
- ToolChain.createLinker() -> createLinker() & createStaticLibraryArchiver()
- Added new CreateStaticLibrary task that doesn't extend AbstractLinkTask
   - Remove options that are not relevant to static libraries
REVIEW-2395: Escape linker args passed to g++ with '-Xlinker'
REVIEW-2425: Added field type
Minor spec update
Reorganise packages for 'cpp' subproject
- org.gradle.plugins.binaries -> org.gradle.nativecode.base
- org.gradle.plugins.cpp -> org.gradle.nativecode.language.cpp
- Moved toolchain implementations into org.gradle.nativecode.toolchain
- Moved cdt stuff into org.gradle.nativecode.cdt
- Moved to use a more standard package structure for model/plugins/tasks/internal