[RELEASE] Released version 1.5-dev2

[RELEASE] Released version 1.5-dev2

Released version 1.5-dev2 with the following main changes :
    - [MINOR] startup: release unused structs after forking
    - [MINOR] startup: don't wait for nothing when no old pid remains
    - [CLEANUP] reference product branch 1.5
    - [MEDIUM] signals: add support for registering functions and tasks
    - [MEDIUM] signals: support redistribution of signal zero when stopping
    - [BUG] http: don't set auto_close if more data are expected