Allow null strings as header value
Change record-id format to use UUID
Change file name format from [0-9]+ to {RECORD-ID}.mhc
Add new headers Mission-Tag and Recurrence-Tag
Allow YYYYMMDD-YYYYMMDD style in X-SC-Day header
Speedup by eliminating unnecessary funcall
Cache the result of mhc-db-scan on creating mini calendars
Add comments about RECURRENCE-TAG structure
Add new command framework to support ``mhc SUBCOMMAND'' style
Remove old README files
Remove old install scripts
Remove Palm support
Set default repository directory
Rewrite core library and delete unused commands
Do not take "2nd May" for "2 May"
Support YYYYMMDD-YYYYMMDD style in X-SC-Day field
Remove old libraries
Rewrite date-enumeration code
New DB scanner using bin/mhc as a backend process
Remove old comments