Fix typo
Add new option --dry-run to SYNC
Small refactoring
Make zsh completion smarter
Remove unused functions
Extract function
Add comment
Replace mhc-db-scan-month to use mhc command
Not to use mhc-slot-get-month-schedule on acquiring filename

mhc-slot-get-month-schedule has large overhead.
It is overkilling for acquiring single filename of an article.
Remove todo and memo features

Since todo and memo features were added in the late history of MHC,
these two features impact on the simplicity of MHC.
To restructure the whole system, I decided to remove them for now.
Use autoload for loading ruby libraries
Small refactoring
Fix typo
Change formatting of Mhc::PropertyValue::Date#to_s
Include year part to mhc scan --format=text
Remove unused methods
Fix cursor-pointing bug after mhc-rescan-month
Use pipe not tty for communicating with mhc process
Remove CVS support
Remove mhc-slot layer

mhc-slot layer is delegated to outer mhc (Ruby) process