Add Http_Handler

- introduce Http module
- add Handler class
Move CM_Request_* into CM_Http_Request_*
Move CM_Response_* into CM_Http_Response_*
enable -webkit-font-smoothing for textareas as well
add textarea to example form, add placeholder
Make placeholder text more visible
adjust default font color / placeholder color
reduce emoticon size
dont use htmlspecialchars
Merge branch 'master' of github.com:cargomedia/CM into issue-1518

Conflicts:
	library/CM/App.php
Adjust CM_Request -> CM_Http_Request
Adjust CM_Response -> CM_Http_Response
Adjust resource vendor test
Move app core SetupScript to http module
lighten placeholder color
Adjust setup scripts naming
Merge pull request #1541 from christopheschwyzer/issue-1541

Improve Typography 3
Merge pull request #1518 from tomaszdurka/issue-1518

Introduce CM_Http module - part of #1519
Merge branch 'master' of github.com:cargomedia/CM into issue-1539
Merge pull request #1539 from mariansollmann/issue-1539

CM_Mail_WelcomeTest dont use htmlspecialchars in CM_Dom_NodeList