'src/generator.ml' is no more.  Instead the generator is logically
split up over many different source files.

Read generator/README for help and tips.

We compile the generator down to bytecode, not native code.  This
means it will run more slowly, but is done for maximum portability.

This commit combines the previously separate "inspector_generator.ml"
program which generated bindings for virt-inspector.

Having two separate programs caused no end of troubles for developers,
so we now combine them into a single program.

NOTE: OCaml xml-light is now *required* in order to rebuild the
generated code.

This change adds an explicit dependency on generator.ml for every file it
generates, except java files. Java is left for another time because it's
considerably trickier.

It also adds a build rule for src/libguestfs.la so it can be rebuilt as required
from other directories.

It does this by creating a top level make file, subdir-rules.mk, which can be
included from sub-directories. sub-directories need to define 'generator_built'
to include local files which are built by generator.ml, and they will be updated
automatically.

This fixes parallel make, and will automatically re-create generated files when
make is run from any directory.

It also fixes the problem which efad4f53 was targetting. Specifically,
src/guestfs_protocol.(c|h) had an erroneous dependency on stamp-generator, and
therefore generator.ml, despite not being directly created by it. This caused
them to be recreated every time generator.ml ran rather than only when
src/guestfs_protocol.x was updated, which cascaded into a daemon and therefore
appliance update.

This patch also changes the contents of the distribution tarball by including
files created by rpcgen.

This commit introduces a generic partition creation interface
which should be future-proof and extensible, and partially
replaces the old sfdisk-based interface.

The implementation is based on parted but is hopefully not too
dependent on the particulars of parted.

The following new calls are introduced:

  guestfs_part_init:
    Initialize a disk with a partition table.  Unlike the sfdisk-
    based interface, we also support GPT and other partition
    types, which is essential to scale to devices larger than 2TB.

  guestfs_part_add: Add a partition to an existing disk.

  guestfs_part_disk:
    Convenience function which combines part_init & part_add,
    creating a single partition that covers the whole disk.

  guestfs_part_set_bootable:
  guestfs_part_set_name:
    Set various aspects of existing partitions.

  guestfs_part_list:
    List partitions on a device.  This returns a programming-friendly
    list of partition structs (in contrast to sfdisk-l which cannot
    be parsed).

  guestfs_part_get_parttype:
    Return the partition table type, eg. "msdos" or "gpt".

The following calls are planned, but not added currently:

  guestfs_part_get_bootable
  guestfs_part_get_name
  guestfs_part_set_type
  guestfs_part_get_type

This commit changes guestfs_launch so that it both launches
the appliance and waits until it is ready (ie. the daemon communicates
back to us).

Since we removed the pretence that we could implement a low-level
asynchronous API, the need to call launch() followed by wait_ready()
has looked a bit silly.

Now guestfs_wait_ready() is basically a no-op.  It is left in the
API for backwards compatibility.  Any calls to guestfs_wait_ready()
can be removed from client code.

(Just whitespace and comment changes, and small restructuring
of the code).

Do it by running this command:
[exempted files are matched via .x-sc_TAB_in_indentation]

  git ls-files \
    | pcregrep -vf .x-sc_TAB_in_indentation \
    | xargs pcregrep -l '^ *\t' \
    | xargs perl -MText::Tabs -ni -le \
      '$m=/^( *\t[ \t]*)(.*)/; print $m ? expand($1) . $2 : $_'