[mapping] refactor mapping extension

* da1ef75 [tree] update based on mapping changes
* 262bff0 [translatable] update mapping and tests
* 3933207 [loggable] update mapping
[tests] upgrade test suite, move under Gedmo namespace

* b223db7 [tests] some updates related to postgresql support
* 3307a4b [tests] adapt as possible to postgresql
* c36ee6e [tree] php5.3 support
* 7ccf2ab [uploadable] migrate mapping and tests
* 4c6dc7a [tests] install phpunit through composer
* 1166e98 [tests] update timeaware softdeleteable test for document
[tree] FIX level in MaterializedPath if 'path_starts_with_separator' or 'path_ends_with_separator' are set
adjustments after rebase
[sluggable] allow to slug identifiers
[references] use manager registry #821