Merge pull request #123 from cs2103aug2014-w15-3J/master

Merge Logic with Master
Added comments
Primary refactoring of Logic. Still requires more refactoring.
Cleaned logic up a bit more
added whitespace for colons
Remove magic numbers and magic strings
Completed the description.
Removed name in comment
Refactored and removed magic constants
Cleaned it up a bit more.
Added more exception catching and log messages
Refactored search manager
Removed name from description
Edited comment position on if-else
edited comments for if-else statements
Added observer pattern in UI
Merge pull request #124 from cs2103aug2014-w15-3J/Logic

Merge Master with Logic
Refactored.
Tidied up the magic constants
Added exception handling in comments