Add syntax for perl5.20 postfix dereference
Add postfix dereferencing to Changes
"Document" perl_no_subprototype_error

We need better docs...
Add build status icon to README
Add test for GH #162 (postfix deref highlighting)
Add test for GH #163 (hash slices)
Merge remote-tracking branch 'upstream/master'

* upstream/master:
  Add test for GH #163 (hash slices)
  Add test for GH #162 (postfix deref highlighting)
  Add build status icon to README
  "Document" perl_no_subprototype_error
  Add postfix dereferencing to Changes
  Add syntax for perl5.20 postfix dereference