Add multichoice support.
Add The phrase "blalba" pattern for highlight.
Merge branch 'master' of git://github.com/charliezhang/nich01as-com into charliezhang-master

Conflicts:
	apps/toefl/data/parser.py
	apps/toefl/data/reading_tpo1-1
	apps/toefl/data/reading_tpo1-3
	apps/toefl/data/reading_tpo10-1
	apps/toefl/data/reading_tpo11-2
	apps/toefl/data/reading_tpo12-1
	apps/toefl/data/reading_tpo13-1
	apps/toefl/data/reading_tpo13-2
	apps/toefl/data/reading_tpo13-3
	apps/toefl/data/reading_tpo14-1
	apps/toefl/data/reading_tpo14-2
	apps/toefl/data/reading_tpo14-3
	apps/toefl/data/reading_tpo16-2
	apps/toefl/data/reading_tpo19-1
	apps/toefl/data/reading_tpo19-2
	apps/toefl/data/reading_tpo2-3
	apps/toefl/data/reading_tpo20-2
	apps/toefl/data/reading_tpo21-1
	apps/toefl/data/reading_tpo22-1
	apps/toefl/data/reading_tpo22-2
	apps/toefl/data/reading_tpo23-3
	apps/toefl/data/reading_tpo24-1
	apps/toefl/data/reading_tpo3-3
	apps/toefl/data/reading_tpo4-1
	apps/toefl/data/reading_tpo4-2
	apps/toefl/data/reading_tpo4-3
	apps/toefl/data/reading_tpo6-2
	apps/toefl/data/reading_tpo6-3
	apps/toefl/data/reading_tpo7-2
	apps/toefl/data/reading_tpo7-3
	apps/toefl/data/reading_tpo8-1
	apps/toefl/data/reading_tpo8-2
	apps/toefl/data/reading_tpo9-2
Add support for highlight sentense.
Fix minor errors.
Fix 19-2
update
Dump to / Load from json