move task convert content to task convertor
delete unnecessary imports
update search method
Merge branch 'master' of https://github.com/cs2103aug2014-w13-4j/main into storage-chuyu
Merge search and filter command
Added command param for complete
combine search and filter in storage
Merge branch 'storage-chuyu' of github.com:cs2103aug2014-w13-4j/main into pn-merge-filter-search

Conflicts:
	src/models/Task.java
Merge branch 'xy-modify-command' of github.com:cs2103aug2014-w13-4j/main into pn-merge-filter-search
combine search and filter tgt in logic
Fix bug
Added in extra complete command for logicapi
Merge branch 'master' of github.com:cs2103aug2014-w13-4j/main into xy-modify-command
Merge branch 'xy-end-date-command' of github.com:cs2103aug2014-w13-4j/main into xy-modify-command
Added date params into search command
Merge branch 'pn-merge-filter-search' of https://github.com/cs2103aug2014-w13-4j/main
Clean up task model
Add isCompleted method
Clean up logic model
Merge branch 'xy-modify-command' of github.com:cs2103aug2014-w13-4j/main into pn-modify-task