vimrc: Fix and improved CScope handler & add Gabs.
vimrc: Fix and improved CScope handler & add Gabs.

The CScope handler was finally useful. It now add all cscope/ctags
files from parent directories of the opened file and the keymapping
only occur if said files are found and cscope is loaded. Also fixed the
annoying waiting time when using ESC. Turns out <C-[> send ESC key. So
it was changed to the original <C-@> (ctrl-space).
Merged some configurations, keymaps and functionalities from
refs/gabs-vimrc.
Also received some bugfix in my function textmode and in general.

rff/cfgbin,rff/cfgbin,rff/cfgbin,rff/cfgbin