Support for undo and redo functions in interface
Merge branch 'master' into interface
Fix bug when reloading the database

Now instance maps are correctly reset when file is rescanned (but this should not happen in the final product)
Add resetDatabase method

resetDatabase() will delete all instances in the database.
This would make LogicTest easier
Return search and view results to menu

Change the result of search and view to be return to menu instead of
printing straight from Logic class
Merge remote-tracking branch 'origin/create_logic'
Updated classpath to include natty lib

natty-0.9.jar will be used as an approved date time lib to parse dates
from natural languages.
Added diagrams folder and diagrams (interface)

For more coherent and unified place to store diagrams for easy
references.
Merge branch 'master' into interface
Merge branch 'interface'
Add a map for displayingId and databaseId
Merge branch 'dbmanager'

Conflicts:
	src/Logic.java
Let all methods in LogicTest throw Exception
Hotfix for executeCommand caused by merging
change update_logic using displayedTaskid
apply changes for update_logic in update tests
add method MarkTaskCompleted()
test of markTaskCompleted
MarkTask test changes
Fix search logic parameter input

Under search command, change the parameter that is being parse in from
getDescription to getKeyword.
And refactored method description