Add debbuild params -i and -a

Closes GH-29 and Debian#738964
Merge commit 'e27af9e'
cmdline: Store arch as string

While at it, reword the help texts a bit
sequencer: Don't run dh_auto_test

Running dh_auto_test can cause the build to fail as, by default,
debhelper does intelligent guessing of what needs to be done for
testing. So, in this case, if setup.py exists, the Debian build system
tries to outsmart everyone and runs, with the system python, `python
setup.py test`

References GH-32
Fix typos and some styles
Refactor: Move dh_virtualenv to a package
Make option parsing using subclass of OptionParser
Deployment: Add method to create new object from options
Support running tests build-time

For now, we only execute `setup.py test` with the virtualenv's python
interpreter.

Closes GH-32
Prepare for 0.7 release
Merge pull request #33 from nailor/fix-testing

Prepare for 0.7 release
JoshK/TomC: fix default for --no-test flag in DebhelperOptionParser
Merge pull request #35 from coggy/fix-test-flag

JoshK/TomC: fix default for --no-test flag in DebhelperOptionParser
doc: Update tutorial as package is now installable for Debian
Merge pull request #36 from nailor/doc-apt-get

doc: Update tutorial as package is now installable for Debian
tutorial: dh-virtualenv is now installable on Trusty
Remove symlinks that point to build environment
Don't break on older ubuntu versions
Don't modify existint relative symlinks

While at it, add tests for symlink handling.

Closes GH-5, thanks @Jc2k!
Merge branch 'fix-symlinks'