Begin v0.6 refurb

Begin v0.6 refurb
Simplify GNUmakefile
Reorganise objects declarations in objects.mk and makefiles
Switch to clang compiler
Switch to gold linker
Stop building deps file on "make clean"
New option to GNUmakefile: SKIPDEPS=1 to skip building deps file
Make build less verbose
New option to GNUmakefile: VERBOSE=1 for all compiler output
Drop obsolete -D__STDC_CONSTANT_MACROS
Drop MVP code from GNUmakefile
Declared C++ standard to be C++14
Enabled many compiler warnings
Removed ticonfig.c
Renamed PLATTFORM_RASPBERRY to PLATFORM_RASPBERRY