gbuild: Gallery: avoid spurious re-delivery

The .sdg/.sdv/.thm files are generated by gengal (i.e. the
Gallery_get_target) but are not targets, which means they will only be
delivered in a second make invocation because make requires running a
command to propagate out-of-date-ness.

Change-Id: Iddb2222151bdbcf93d79bd801fa30ab7d7fbd1d3
gbuild: HelpTarget: need more recipes...

The files in gb_HelpTarget__get_index_files need to be targets with a
rule since they are delivered via Package.  Same for the ".tree" file,
and the HelpJarTarget.

Change-Id: I03167f358aabf297c9f2feacc170ec4e9db437d1
gbuild: SdiTarget: avoid more spurious rebuilds...

... because the .hxx file only occurs as a target in .d files of
objects, the rule for it will not trigger in a build from scratch and it
will be older than the SdiTarget itself and will be touched on the next
incremental build.  Ensure that it's not older than the SdiTarget.

Change-Id: I49504814ff62efb22d1f10b37e3bec2ea841bfc9
clean up #ifdef ICC code

According to the dmake documentation, ICC refers to Visual Age C++ for
OS/2, which is not a supported compiler (or platform).

Change-Id: Ic9e23bc7c44de110a3a312bd007beda3b660927d
get-bugzilla-attachments-by-mimetype: IANA has 2 mime-types for WPD

... on https://www.iana.org/assignments/media-types/application

Also fix up the common_noncore_mimetypes while there.

Change-Id: I66eb74b0906a10893a771b7136b5f6ebda938ee6
get-bugzilla-attachments-by-mimetype: port to Python 3 syntax

Change-Id: I928eb1baa7390301036585d84895f44eb4c38d20
get-bugzilla-attachments-by-mimetype: make this run on Python 3

Change-Id: I27cf30c62122ea191c852a1a298a40ef64d35ba9
get-bugzilla-attachments-by-mimetype: fix the lanuchpadlib mess

Apparently somebody found it a good idea to remove the getBugTasks()
method.  Also the darn thing won't run on Python 3.  So apparently it's
mostly unmaintained, except that functions that we need are removed.

For future reference: it can be installed on non-Ubuntu systems by:
    pip install -v --user launchpadlib

Change-Id: Ib7b0a46011dffcfe091f5bb73ed19b9dc311046c