- switch to Struts 2.3.15.2
- removed dynamic method invocation disabling, since this is the new default in Struts 2.3.15.2
- added example option to switch default theme
Merge branch 'master' into bootstrap-theme-starter

Conflicts resolved:
	src/main/resources/struts.xml
Merge branch 'master' into bootstrap-theme-starter

Conflicts resolved:
	src/main/resources/struts.xml