BS-2038 : Create the service to manage L'n'F object

Changes :
- Create ThemeService with requests
- Create SQL scripts & Hibernate Mapping
- Create unit tests
- Create builder, factory, server objects
- Modify configuration (XML files)
BS-2396 : New API methods: add or update; getcurrent, getdefault, getLastUpdatedate for mobile and portal

Changes :
- Create client object & get method API
BS-2396 : New API methods

Changes :
- Implement API methods
- Add new service methods
- Add tests
- Add API Accessor
- Modify SearchDescriptors
BS-2397 : Import default L'n'F at the tenant creation
BS-2397 : Import default L'n'F at the tenant creation

Changes :
- Create a platform delegate
- Add unit tests on the delegate
- Add integration tests
- Import ZIP files, and unzip one, when create tenant
- Add util methods to unzip ZIP file
- Create default theme, when create tenant
- Modify theme table to have no css mandatory.
Revert bad remove
BS-2397 : Import default L'n'F at the tenant creation

Changes :
- Don't throw an axception if default theme files don't exist in classpath.
BS-2038 : Create the service to manage L'n'F object

Changes :
- Modify MySQL script (replace bad character " by ')
Fix bad drop of foreign key in MySQL
Revert "Fix bad drop of foreign key in MySQL"

This reverts commit 46f3c13122671df45bd2a12d6d98953baf4cb6e8.
Fix bad drop of foreign key in MySQL
Add content to zip file for themes (Oracle don't want to store a file empty)
Merge branch 'origin/master'
Merge branch 'master' into BS-2037
Merge branch 'master' into BS-2037

Conflicts:
	bpm/bonita-core/bonita-process-engine/src/main/java/org/bonitasoft/engine/api/impl/ProcessAPIImpl.java
Merge branch 'BS-2037'