Minor Mending

Whole bunch of somewhat minor fixes:

* Markdown rendering for readmes (by @prologic)
* More CSS fixes across the board
* The git executable is no longer required in PATH as git-upload-pack is
  now implemented using go-git

Written in Go

Second and probably the last major release of legit. Here are the
highlights:

* Bunch of CSS tunings by @e-zk and @cblgh
* Generally finalized styles & templates througout
* Doesn't spew binary garbage in the file view
* Link to parent commit in commit view by @phirecc
* Support for unveil(2) (on OpenBSD) by @e-zk
* Config option repo.ignore to ignore repos

First release of legit