Mass code cleanup and other janitorial work

• Reformat code into X.Org standard coding style
• Remove register keyword from variable declarations
• Variable scope reduction as suggested by cppcheck
• Store predefined -D values in const char fields
• find_includes: rename variables to avoid shadowing global
• quoteColons: Remove redundant initialization of tmp
• Use reallocarray() on systems that provide it
• Handle some implicit conversion warnings from clang
• Stop casting _parse_data pointers through (char *) and back
• cppsetup: use C99 struct initialization
• Make malloc error checking/reporting more consistent
• Cache filename after realpath() processing
• Call strrchr() instead of hand coding a custom version
• Make more things static that aren't needed in more than one file