modhtp: Better handle cases in which the libhtp parser gives up
libhtp: Sync with upstream 0.5.x branch.
Squashed 'libs/libhtp/' changes from 685b183..700fb5e

700fb5e Tidy up.
73392c4 Fix HTP_MULTI_PACKET_HEAD when processing requests with trailers.
f77579c Change all hooks to use htp_tx_t references (instead of htp_connp_t references).
86024a1 Add more tests for invalid requests.
1c31149 Do not stop processing request headers if C-L is invalid. Processing will now stop after the REQUEST_HEADERS hook. New flags: HTP_REQUEST_INVALID and HTP_REQUEST_INVALID_C_L.
9184921 Fix TRANSACTION_COMPLETE not being invoked in hybrid mode.
9bbe5a9 Do not allow incomplete transactions to be destroyed.
559f74d Do not forget to complete a successful CONNECT request.
2380dfe New callback TRANSACTION_COMPLETE.
a373fbd Tidy up.
f539985 Split htp_tx_t::progress into two fields, one for requests and one for responses. This allows us to track progress separately (which is sometimes needed).

git-subtree-dir: libs/libhtp
git-subtree-split: 700fb5e64c39cbe0999bd01e1f0cdcc36066c17f
modhtp: Update callbacks due to libhtp API changes.
modhtp: Update added/renamed parser flags.
Squashed 'libs/libhtp/' changes from 700fb5e..5c1c5ad

5c1c5ad Fix memory leak on a partially processed response.
4c813c3 Fix memory leak.
369fa3f Fix memory leak in a test.
34376e8 Fix invalid read.
f88103e Fix invalid read.
3f5ef21 Fix memory leak in a test.
6c421f4 Fix a memory leak.
28bc0d6 When destroying an entire connection, destroy transactions even when they are incomplete.
dfb6836 Fix off-by-one invalid read.
88ddac0 Fix endless loop in htp_decode_path_inplace and htp_decode_urlencoded_inplace.
b5307aa Tidy up.
73e7931 Fix removing htp_tx_t references from htp_connp_t on transactions where responses complete first.
d861071 Do not access transaction data after transaction has been destroyed.

git-subtree-dir: libs/libhtp
git-subtree-split: 5c1c5ad773b0bfa9855fa3f3635062aa08f3a7d8
libhtp: Sync with upstream 0.5.x branch.
auditlog: Do not overwrite a tx-msg with empty message.