updated readme and started polishing code. A lot left before this branch is ready for prime time
finished polishing the code for now. Implemented the missing parts of the api and added fastscroll+sectionindexer to the sample/test project
selector is now correctly positions on top of only the item and not the header when clicking an item
shortened some internal class names
fixed order datasetobservers are called
added a test in the sample project to make sure everything works when changing data
added tests to sample app and fixed datasetobservers recessive loop
added demo gif
fixed readme
updated readme
handle setting a null adapter
added xml preview code from master branch
fixes the long standing view pager rendering bug. fixes #72
made sure choice mode works
added header background selector to sample project
Merge branch 'dev_old_tactic'

Conflicts:
	README.md
	library/src/com/emilsjolander/components/stickylistheaders/AdapterWrapper.java
	library/src/com/emilsjolander/components/stickylistheaders/CheckableWrapperView.java
	library/src/com/emilsjolander/components/stickylistheaders/StickyListHeadersListView.java
	library/src/com/emilsjolander/components/stickylistheaders/WrapperView.java
	sample/res/layout/header.xml
	sample/res/layout/main.xml
	sample/src/com/emilsjolander/components/stickylistheaders/test/TestActivity.java
	sample/src/com/emilsjolander/components/stickylistheaders/test/TestBaseAdapter.java
cleaned up from the merge