vimrc :: regexpengine=1 does not make a difference in 90% of the cases

Signed-off-by: BlackEagle <ike.devolder@gmail.com>
plugin : add undotree

Signed-off-by: BlackEagle <ike.devolder@gmail.com>
vimrc :: add F7 as undotree shortcut

Signed-off-by: BlackEagle <ike.devolder@gmail.com>