Add other g* commands to go with gj, gk, etc.

Added maps in .vimrc for:
g$, g^, g0, g<Home>, g<End>
Merge pull request #466 from memotype/3.0

Add other g* commands to go with gj, gk, etc.
Updated description of nowrap command

Synced the description comment with the command.
Assumed comment was wrong instead of the command.
No offense, but isn't `set wrap` more comfortable? :)
Add `<leader>gw :Gwrite<CR>` mapping to Readme
Merge pull request #469 from swapnilmj/3.0

Updated description of nowrap command
Merge remote-tracking branch 'upstream/3.0' into 3.0
update