Merge pull request #233 from miroslavhajek/develop

Merge feature/backend into develop
Symbolic Reference convertor - WIP
Merge remote-tracking branch 'v2/develop' into feature/referential-integrity
VP-1 Replacing of URLs and symbolic references in entities and html files
Merge pull request #234 from dlu-gs/feature/referential-integrity

Feature/referential integrity
VP-69 Simple PHP renderer implementation and factory for mail
Merge pull request #235 from dlu-gs/feature/simple-php-renderer

VP-69 Simple PHP renderer implementation and factory for mail
Link content bug
Merge pull request #236 from dlu-gs/hotfix/symref

Link content bug
VP-75 Content type Link display on FE fixed
Merge pull request #237 from dlu-gs/hotfix/content-link

VP-75 Content type Link display on FE fixed
VP-1 Symbolic references in files are correctly translated to URLs on front-end
Merge pull request #238 from dlu-gs/hotfix/sym-refs-fe

VP-1 Symbolic references in files are correctly translated to URLs on fr...
VP-73, VP-9 Explorer create folder fix
Merge pull request #239 from dlu-gs/hotfix/create-folder

VP-73, VP-9 Explorer create folder fix
VP-81 AJAX field validation
Merge pull request #240 from dlu-gs/feature/forms

VP-81 AJAX field validation
VP-8 Refactoring for ZF 2.0.8
VP-8 Routing and response workflow (StreamResponse and
StreamResponseSender)
Merge pull request #241 from dlu-gs/hotfix/zf21

Upgrade to ZendFramework 2.1.4 and corresponding refactoring