changed TimePeriod to public
Searche added
CompareTo implemented in DateTime.java
trying to implement the help text
added in searchfree command    format searchfree <date>   or searchfree startDate-endDate
Improved on HelpManager
Merge remote-tracking branch 'origin/AutoHelp' into UI
Merge remote-tracking branch 'origin/AutoHelp' into UI
Editted some commands in HelpManager
edit the help page
Merge branch 'UI'
fix the bug of displaying current time
support display for searching free slot, free slots will be marked in green
embed the font in the project file
change helpManager to final
take command added
Merge branch 'parser'
bug in edit time fixed
Merge remote-tracking branch 'origin/master' into AutoHelp