Misc: Separate nano from version.h

Misc: Separate nano from version.h

* As version.h processed by autotools, the automatic updating of the
  nano there can result in unneeded reconfs (eg. after issuing a git
  pull, regardless of whether the conf is still valid)
* Avoid this by placing the nano in its own file, as it won't be
  processed by autoconf. This also simplifies the versioning git hooks
  and removes the sed dependency.