* Cherry-pick the following patches from 1.5.9 release:
    - 8a0b93bde77e BUG/MAJOR: sessions: unlink session from list on out
                              of memory
    - bae03eaad40a BUG/MEDIUM: pattern: don't load more than once a pattern
                               list.
    - 93637b6e8503 BUG/MEDIUM: connection: sanitize PPv2 header length before
                               parsing address information
    - 8ba50128832b BUG/MAJOR: frontend: initialize capture pointers earlier
    - 1f96a87c4e14 BUG/MEDIUM: checks: fix conflicts between agent checks and
                               ssl healthchecks
    - 9bcc01ae2598 BUG/MEDIUM: ssl: force a full GC in case of memory shortage
    - 909514970089 BUG/MEDIUM: ssl: fix bad ssl context init can cause
                               segfault in case of OOM.
* Cherry-pick the following patches from future 1.5.10 release:
    - 1e89acb6be9b BUG/MEDIUM: payload: ensure that a request channel is
                               available
    - bad3c6f1b6d7 BUG/MEDIUM: patterns: previous fix was incomplete