Task@17503 - Validate Emails - optimizations.

- Fetch all the cached emails first in one call.
- Control the parallelism of the resolvation requests;
  default is 2 (the client will send 2 concomitent requests to the server)
- Factor out duplicate js code.

git-svn-id: https://svn.eionet.europa.eu/repositories/Naaya/trunk/eggs/naaya.content.talkback@20513 a0171fae-0946-0410-966d-b1775066cd26
task#17503 update changelog

git-svn-id: https://svn.eionet.europa.eu/repositories/Naaya/trunk/eggs/naaya.content.talkback@20518 a0171fae-0946-0410-966d-b1775066cd26
release 1.4.26, new version 1.4.27

git-svn-id: https://svn.eionet.europa.eu/repositories/Naaya/trunk/eggs/naaya.content.talkback@20520 a0171fae-0946-0410-966d-b1775066cd26
Corrected current version

git-svn-id: https://svn.eionet.europa.eu/repositories/Naaya/trunk/eggs/naaya.content.talkback@20522 a0171fae-0946-0410-966d-b1775066cd26