Removes shelltype option and all revelant doc. #1249

Fixes #1240
doc: remove legacy os_*.txt

keeping os_dos.txt, see #1115
doc: remove gui_w16.txt
doc: remove if_sniff.txt
doc: remove if_ole.txt
doc: remove workshop.txt
doc: remove netbeans.txt
doc: remove documentation for `:shell`

see #450
doc: cleanup

  * fix some links
  * typo
  * remove reference to hangul_input
  * remove unused vim2html.pl
doc: remove links to non existent files
Merge pull request #1268 from stefan991/cleanup-docs-2

Cleanup user documentation
Mark patches 363 and 366 NA.
vim-patch:7.4.375

Problem:    Test 63 fails when run with GUI-only Vim.
Solution:   Add guibg attributes. (suggested by Mike Soyka)

https://code.google.com/p/vim/source/detail?r=v7-4-375
Merge pull request #1254 from splinterofchaos/na-patches

Mark patches 363 and 366 NA; vim-patch:7.4.375
homebrew: use Makefile-defined defaults. #1259

Assuming homebrew always uses a clean workspace, a separate "cmake" step
is not necessary.
version: update user-facing version indicators

- VIM_VERSION_LONG and VIM_VERSION_LONG_DATE do not affect plugins,
  they are only cosmetic.
- Vim-related version identifiers will be preserved for plugin
  compatibility (has("patchXXX") and v:version).
version: remove "Included patches" message

It is meaningless to Nvim.
version: remove non-functional Vim version identifiers
version: report commit hash as "build number" in long version string
version: generate "build number" from commit timestamp

- cmake: git_timestamp() returns last commit time formatted as
  `YYYYMMddHHmm`.
- Always include commit hash in :version and --version output.

`nvim --version` sample output:
  NVIM 0.0.0-alpha+201410070245 (compiled Oct  7 2014 05:30:45)
  Commit: f747b2b1ff7bfe7eb00cc2be82d7af87c98f1111