fix #1285: add a check for null host when validating user entered url
code style
rename isValidUrl to isValidUrlAndHostNotNull
Merge pull request #1290 from wordpress-mobile/issue/1285-null-host-setupblog

fix #1285 npe in setupblog
Primary tag is no longer set if it matches one of the default tag names
2.8 version bump
Primary tag now uses the same blue tag icon as stats
Merge branch 'develop'

Conflicts:
	src/org/wordpress/android/util/UrlUtils.java
Primary tag is hidden when it's the same as the selected tag
* Renamed "blog detail" to "blog preview" internally
* Activity title for blog preview is now "Preview Blog" rather than the blog name
* Activity title for tag preview is now "Preview Tag" rather than the tag name
* Tag preview now enables viewing other tapped tags
Added secondary tag to post list, shows the 2nd most popular tag when the most popular matches the currently selected one.
Tag preview header is now fixed - doesn't scroll with the listView
Fixed bug that caused tag preview header to be too wide on tablets
Fixed bug that caused primary tag preview to appear even when secondary tag clicked
Merge branch 'develop' of https://github.com/wordpress-mobile/WordPress-Android into feature/1266-reader-show-tags