Merge branch 'release/0.2.0' into develop
vimrc now checks to see if par exists before using it.

Otherwise the building format program is used.
Silently fail guifont=PragmataPro if the font is not installed.

Whatever the default on the system is will be used.
Updated README for 0.2.1.
Releasing 0.2.1: Safety checks for par formatprg and PragmataPro font.