Tender modifcations.
Returns are always considered negative enteries
Retruns must be exact.
Negative values will not be accepted on non returns.

Conflicts:
	pos/is4c-nf/lib/Tenders/CreditCardTender.php
	pos/is4c-nf/lib/Tenders/TenderModule.php
Tare weight prompt plugin. Configureable default for non entrey. First uses item tare first. prompts if there is none

Conflicts:
	pos/is4c-nf/parser-class-lib/parse/UPC.php

Conflicts:
	pos/is4c-nf/parser-class-lib/parse/UPC.php
Missed some hard coding test cases in the tare prompt.
Added a special department for paidouts.
Added a special department that reverses the value entered and propts for a reason.
Also added the gui-modlue nessadary for the promt.
Merge pull request #328 from FranklinCoop/core_master

Pull Request from FranklinCoop
BUGFIX: report_headers() in xls

$this->report_headers, not $this->report_headers()
Merge remote-tracking branch 'origin/master' into posDevelop
New API module for rewriting variable weight UPCs