Change required jre to 1.7 from 1.6

New issue
Summary: Require JRE 1.7 instead of EOL-ed JRE 1.6
Status: Started
Owner: snswinhaiku.lo@gmail.com
Labels: Type-Enhancement Priority-High OpSys-All Maintainability
JRE 1.6 is (will be?) EOL-ed. Use JRE1.7!!
Bump logback and slf4j version
Remove unused throw statement
Deprecate Utility#equalString()

Use string-switch
Generify
Merge branch 'jre1.7'

Conflicts:
	elnetw-launcher/src/main/java/jp/syuriken/snsw/launcher/TwitterClientLauncher.java