First setup experience

[marcelhollerbach]

Hello,

i started to use this plugin yesterday. I pretty much like the "autoconfigure" idea of it.

A few problems happend when i started to work with it.

• flags.make was parsed a bit wrong, for C projects CFLAGS is the flag to look for not CXXFLAGS
• compiler_commands.json parses the flags a bit wrong, it takes all flags except -g and stops if -o or -c was specified. Problem here is that the compiler flags do not need to follow a specific order, so after a -o/-c a -I can still happen, so a few flags are probebly lost
• It would be super usefull if the error highlighting could be added, so errornous lines where underlined red.

(I addessed the first two issues in a PR)

Otherwise awesome plugin!

[pfultz2]

Ok so I added fixes for the first to issues on develop branch.