Don't remap <CR> for omnicomplete it causes issues

fixes issue #280
Improve the readme showing an option to configure the
enviroment variables because they are not set by default by
gVim.
improve rust and puppet support
Improve the readme to show an option to configure the
environment variables because they are not set by
default with gVim.
Bugfix #320. vimdiff "]c" jump to next diff doesn\'t work #320. Thanks the help from @keelerm84 and @pwolfram
Merge pull request #636 from chrisnicola/dont-remap-cr

Don't remap <CR> for omnicomplete it causes issues
Merge pull request #657 from yssource/3.0

Bugfix #320. vimdiff "]c" jump to next diff doesn't work
Merge pull request #654 from gmunumel/3.0

Improve the readme to show an option to configure the
Merge pull request #651 from globin/rust_puppet

improve rust and puppet support
Merge pull request #649 from gmunumel/improve_readme

Option to configure environment variable
Merge remote-tracking branch 'upstream/3.0' into 3.0