Removed unnecessary PATHS from cmake modules

- DEPS_INSTALL_DIR is already set into CMAKE_PREFIX_PATH in
  the main CMakeLists.txt
Merge #910 'Remove unnecessary PATHS from cmake modules'
neovim.rb: modernize the style

https://github.com/styleguide/ruby
neovim.rb: improve dependency

1. remove unnecessary deps `md5sha1sum`
2. add `=> :build`
3. add missing deps `autoconf`
Merge pull request #922 'Improve neovim.rb'
Replace int with bool in some files. #654
Replaced most TRUE/FALSE macros in arabic, mbyte and spell. #645
remove proto.h include from vim.h
remove stdbool.h include from vim.h and globals.h
move memory.h include to version.c
move ascii.h include out of vim.h
move locale.h include out of vim.h
move <inttypes.h> include out of vim.h
move wctype.h include out of vim.h
move assert.h include out of vim.h
move stdarg.h include out of vim.h
move errno.h include out of vim.h