Try to fix Issue #4

Created a function to manipulate query part of Url such that  if the
form Url already contains aquery, the stept query is appended to that
query, this allowing Urls like: {server}/page.html?form=3&step=1.
fixed missing content escaping in input value
See Issuee #3.
Created method getValuesWithLabel() which return an array containing both value and label.
Merge branch 'master' of github.com:onlysli/depage-forms into dev