[MERGE] SourceLayout: src/base, take 0

Hello,

    In preparation for src/{ICAP,eCAP} move to src/adaptation, I needed
to move AsyncJob.* files away from src/ICAP/. I have decided to put them
into the new src/base directory until a better place is found. While
adding src/base, I discovered and started to fix a few problems with
adding more src/ subdirectories.

These changes are small steps towards a nice layout. I wanted to post
them anyway because they affect a couple of strange places in our
Makefiles (e.g., src/ip found in the top-level Makefile and seemingly
bogus cf_gen dependencies).

I also wanted to ask whether AsyncJob and related Async* classes belong
to src/base/ or their own subdirectory. If we want a separate dir,
should we use src/jobs/ or perhaps src/calls (keeping in mind that not
all calls are between jobs and that jobs do more than just async calls)?
Probably not src/async as that clashes with I/O APIs.

Detailed change log is below.

Thank you,

Alex.

=== modified file 'Makefile.am'

Removed src/ip from the top-level SUBDIRS list. That directory is not
a top-level subdirectory and it is already listed in src/Makefile.am.

The commit message introducing the change talked about libip being a "POD
library". I do not know what that is, but, hopefully, we do not really
need to
make this kind of exceptions for any src/ libraries.

=== added file 'src/common.am'

Copied common Makefile.am stuff seen in a few Makefile.ams to a single
Makefile "header". This avoids evil code duplication. This file should be
included by most Makefile.ams inside src/. Needs more work as some of the
copied code is questionable and more code can probably be extracted
here. See
XXXs.

TODO: The .h dependency test script part seems pretty universal, but if
many subdirs need to customize it, we may want to put it into a separate
Makefile "header".

=== modified file 'src/AsyncJobCalls.h'
=== modified file 'src/BodyPipe.h'
=== modified file 'src/Server.h'
=== modified file 'src/adaptation/AccessCheck.h'
=== modified file 'src/adaptation/Initiate.h'
=== modified file 'src/adaptation/Initiator.h'
=== modified file 'src/client_side.h'
=== modified file 'src/client_side_request.h'

Moved src/ICAP/AsyncJob.* to src/base/ to prepare for the src/ICAP move to
src/adaptation/icap.

=== added dir 'src/base'
=== added dir 'src/base/Makefile.am'
=== modified file 'src/Makefile.am'
=== modified file 'configure.in'

Added src/base directory for fundamental, commonly-used code pieces that are
not large enough to warrant their own directories. Currently base/ contains
the beginning of AsyncCalls hierarchy, which may eventually get its own
directory.

=== modified file 'src/Makefile.am'

Reduced cf_gen dependencies so that it can be built before subdirectories,
as, apparently, required by BUILT_SOURCES.

Moved some libraries that are used by virtually all executables to
COMMON_LIBS.
The list will probably grow as we try to reduce the insane complexity of the
current Makefile.am.