Fix guicmd execution when filename includes single quote
Merge pull request #403 from joker1007/fix_guicmd_single_quote_filename

Fix guicmd execution when filename includes single quote
- Fixed #404 open files by relative path.
- Fixed mappings.
- Deleted debug message.
- Fixed #405 converters.
- Improved example.
- Improved error messages.
- Fixed #406 converts to home base path in bookmark source.
- Improved mru file format.
- Fixed alias problem.
- Must reload mru candidates when exiting Vim.
- Improved documentation for line source.
- Fixed restore current directory behavior.
- Fixed mru errors.
use noautocmd to suppress side effects (for example, lcd in BufEnter)
Merge pull request #408 from itchyny/useNoautocmd

use noautocmd to suppress side effects (for example, lcd in BufEnter)
- Fixed mru save behavior.
- Improved diff action behavior.
- Fixed wrap behavior in line source.