tests/test-tools.t

debian: switch to using debhelper and dh_python2 to build debs

This is a much larger commit than I'd like, but I honestly don't see a
good way to break it up and leave things working. Summary:

We now use debian/rules with debhelper to build our debs. This is much
more standard, and means we use dh_python2 to do things like handle
leaving .pyc files out of the built debs.

The resulting package is split into mercurial and mercurial-common,
with the former being the hg stub and all the native .sos, and the
latter being basically everything else.

builddeb and dockerdeb are updated to use the new system. The old way
(using dpkg by hand) breaks with the above changes because
debian/control no longer contains a version string (that's now guessed
from the phony changelog.)

Tests are updated to assert that the right files end up in the right
debs.

Tests of the file helper tool

  $ f -h
  ?sage: f [options] [filenames] (glob)
  
  ?ptions: (glob)
    -h, --help            show this help message and exit
    -t, --type            show file type (file or directory)
    -m, --mode            show file mode
    -l, --links           show number of links
    -s, --size            show size of file
    -n NEWER, --newer=NEWER
                          check if file is newer (or same)
    -r, --recurse         recurse into directories
    -S, --sha1            show sha1 hash of the content
    -M, --md5             show md5 hash of the content
    -D, --dump            dump file content
    -H, --hexdump         hexdump file content
    -B BYTES, --bytes=BYTES
                          number of characters to dump
    -L LINES, --lines=LINES
                          number of lines to dump
    -q, --quiet           no default output

  $ mkdir dir
  $ cd dir

  $ f --size
  size=0

  $ echo hello | f --md5 --size
  size=6, md5=b1946ac92492d2347c6235b4d2611184

  $ f foo
  foo: file not found

  $ echo foo > foo
  $ f foo
  foo:

#if symlink
  $ f foo --mode
  foo: mode=644
#endif

  $ python $TESTDIR/seq.py 10 > bar
#if unix-permissions symlink
  $ chmod +x bar
  $ f bar --newer foo --mode --type --size --dump --links --bytes 7
  bar: file, size=21, mode=755, links=1, newer than foo
  >>>
  1
  2
  3
  4
  <<< no trailing newline
#endif

#if unix-permissions
  $ ln bar baz
  $ f bar -n baz -l --hexdump -t --sha1 --lines=9 -B 20
  bar: file, links=2, newer than baz, sha1=612ca68d0305c821750a
  0000: 31 0a 32 0a 33 0a 34 0a 35 0a 36 0a 37 0a 38 0a |1.2.3.4.5.6.7.8.|
  0010: 39 0a                                           |9.|
  $ rm baz
#endif

#if unix-permissions symlink
  $ ln -s yadda l
  $ f . --recurse -MStmsB4
  .: directory with 3 files, mode=755
  ./bar: file, size=21, mode=755, md5=3b03, sha1=612c
  ./foo: file, size=4, mode=644, md5=d3b0, sha1=f1d2
  ./l: link, size=5, md5=2faa, sha1=af93
#endif

  $ f --quiet bar -DL 3
  1
  2
  3

  $ cd ..

Yadda is a symlink
#if symlink
  $ f -qr dir -HB 17
  dir: directory with 3 files
  dir/bar:
  0000: 31 0a 32 0a 33 0a 34 0a 35 0a 36 0a 37 0a 38 0a |1.2.3.4.5.6.7.8.|
  0010: 39                                              |9|
  dir/foo:
  0000: 66 6f 6f 0a                                     |foo.|
  dir/l:
  0000: 79 61 64 64 61                                  |yadda|
#else
  $ f -qr dir -HB 17
  dir: directory with 2 files (esc)
  dir/bar: (glob)
  0000: 31 0a 32 0a 33 0a 34 0a 35 0a 36 0a 37 0a 38 0a |1.2.3.4.5.6.7.8.|
  0010: 39                                              |9|
  dir/foo: (glob)
  0000: 66 6f 6f 0a                                     |foo.|
#endif