Various minor tweaks to CLCompatOptions.td

- Add back indentation I accidentally removed in r364901
- Wrap two lines to 80 cols
- Slightly tighten up help text for several flags
- Consistently use "Do not" instead of "Don't"
- Make every option description start with a verb
- Use "Set" instead of "Specify"
- Mark default values of options more consistently
- Remove text about "/Zi" not producing PDBs since it's confusing
  for people not intimately familiar with the implementation of
  the normal PDB pipeline. /Zi lets the linker produce PDBs, which
  is what most users want.
- Consistently use "file" over "filename" in meta var names,
  consistently use "file name" over "filename" in text
- Make all output setting options have consistent language

llvm-svn: 365721