Update README.md
Update documentation.pstar
Merge pull request #22 from geirda/patch-2

Update documentation.pstar
Merge pull request #21 from geirda/patch-1

Update README.md
Update why_pstar.pstar
Update how_to_get.pstar
Update what_is.pstar

Fixed a typo
Merge pull request #23 from geirda/patch-3

Update why_pstar.pstar
Merge pull request #25 from geirda/patch-5

Update what_is.pstar
Merge pull request #24 from geirda/patch-4

Update how_to_get.pstar
Merge pull request #26 from atlesn/master

Fix web page incompatibilities
Add test case for empty strings
Merge branch 'master' of https://github.com/P-star/P-star
Add ! operator to string to check for empty strings. Add test result.
Update readme
Merge remote-tracking branch 'pstar_master/master'