introduce generic function, which puts braces around macros

- introduce embrace_macros()
- define keywords
- remove lines replacing known macros to the form with braces
don't add `-q' to %setup, it is there by default
mark DESTDIR match as very poor and to be reworked
replace jobs macro code with regexp

- replace code matching list of substrings with one regexp,
  it will simplify the code and produce better results
make the license_changes.txt configuration with full path
simplify regexp for macros
don't check input file suffix

It's not useful at all.
finish putting braces around macros (ignore macros with arg)

- remove re_keywords completely - not used
- parse `rpm --showrc' output to identify macros with argument
  (macro functions)
- parse processed spec file to identify macro functions, this is done within
  RpmSpecCleaner class so it can be called for multiple files