vim: update indentLine

Merges 2 commits from github.com:nixprime/indentLine.git:
- bb633f3fb2 "Fix filetype filtering"
- 0d05abd79c "add the g:indentLine_setColors option"
color tuning

Make jcolor_dark's foreground_weak even darker, since it doesn't have
enough contrast with foreground_deemph otherwise.
vim: use dotted line for leading indentation