Change "manifesto post" text to "manifesto item"

reference code4aap/swaraj.commons#24

In commons_post.module, change some human readable name

"manifesto post" -> "manifesto items"
"create a post" -> "create a manifest item"
Merge branch 'issue24' of github.com:akashjain132/swaraj.commons into akashjain132-issue24

Conflicts:
	docroot/profiles/commons/modules/contrib/commons_posts/commons_posts.module