A modified patch from Ankit Jain for "We should check that the thru date is not same or older than the from date" https://issues.apache.org/jira/browse/OFBIZ-3161

jleroux: 
I reused Ankit's patch as a basis for this commit
I added an i18n label
Added a way to use alert() in showErrorAlertLoadUiLabel for generalising when no contentarea is present
Replaced $ call by jQuery
Used the <<name*='fromDate'>> and <<name*='thruDate'>> filters to get all cases (228 thruDate cases)
Still used only an alert, so it's only a warning, nothing coercive

There are other date couples like (estimatedStartDate, estimatedCompletionDate) and (actualStartDate, actualCompletionDate) but their values should not be enforced.
If ever someone wants to not let them free, then she just has to add the couples in FromThruDateCheck.js





git-svn-id: https://svn.apache.org/repos/asf/ofbiz/trunk@1598977 13f79535-47bb-0310-9956-ffa450edef68