Fix conditional in vimrcs/extended.vim

In the font section change has("linux") to has("unix").
Vim does not have "linux" feature only "unix".
Updated all the plugins. Removed powerline. Added vim-airline (replacement for powerline). Added vim-fugitive.
Merge pull request #28 from CrypticStranger/fix-os-conditional

Fix conditional in vimrcs/extended.vim
Update README.md

Updated link to ack.vim
pretty sure .svn not needed anymore
updated link for zencoding
Updated plugins. Fixed some issues related to empty space and peaksea. Using Source Code Pro as default font
Added vim-zenroom: Remove all clutter and focus only on the essential. Similar to iA Writer or Write Room
Merge branch 'master' of github.com:amix/vimrc

Conflicts:
	vimrcs/extended.vim
Updated vim-zenroom
Promote SOurce Code Pro
.
Fixed a typo. Added the shotcut for vim-zenroom.
Move into right section (documentation of zenroom)
Added goyo.vim and vim-zenroom2
Added tags
Fixed some issues with terminal setup
.
Readded goyo.vim
.