Notable changes:
- libmagic is no longer used at all. All MIME type detection is
done through new Bro signatures, and there's no longer a means to get
verbose file type descriptions (e.g. "PNG image data, 1435 x 170").
The majority of the default file magic signatures are derived
from the default magic database of libmagic ~5.17.
- File magic signatures consist of two new constructs in the
signature rule parsing grammar: "file-magic" gives a regular
expression to match against, and "file-mime" gives the MIME type
string of content that matches the magic and an optional strength
value for the match.
- Modified signature/rule syntax for identifiers: they can no longer
start with a '-', which made for ambiguous syntax when doing negative
strength values in "file-mime". Also brought syntax for Bro script
identifiers in line with reality (they can't start with numbers or
include '-' at all).
- A new Built-In Function, "file_magic", can be used to get all
file magic matches and their corresponding strength against a given
chunk of data
- The second parameter of the "identify_data" Built-In Function
can no longer be used to get verbose file type descriptions, though it
can still be used to get the strongest matching file magic signature.
- The "file_transferred" event's "descr" parameter no longer
contains verbose file type descriptions.
- The BROMAGIC environment variable no longer changes any behavior
in Bro as magic databases are no longer used/installed.
- Reverted back to minimum requirement of CMake 2.6.3 from 2.8.0
(it's back to being the same requirement as the Bro v2.2 release).
The bump was to accomodate building libmagic as an external project,
which is no longer needed.
Addresses BIT-1143.
Add a "broxygen" domain Sphinx extension w/ directives to allow
on-the-fly documentation to be generated w/ Bro and included in files.
This means all autogenerated reST docs are now done by Bro. The odd
CMake/Python glue scipts which used to generate some portions are now
gone. Bro and the Sphinx extension handle checking for outdated docs
themselves.
Parallel builds of `make doc` target should now work (mostly because
I don't think there's any tasks that can be done in parallel anymore).
Overall, this seems to simplify things and make the Broxygen-generated
portions of the documentation visible/traceable from the main Sphinx
source tree. The one odd thing still is that per-script documentation
is rsync'd in to a shadow copy of the Sphinx source tree within the
build dir. This is less elegant than using the new broxygen extension
to make per-script docs, but rsync is faster and simpler. Simpler as in
less code because it seems like, in the best case, I'd need to write a
custom Sphinx Builder to be able to get that to even work.
