Update .gitignore:

* ignore /tests/... (was still /buildtests/...)
* ignore /dist/, too
* ignore directories, where directories are meant
* changes /e2etests to /old/e2etests (was moved there)
Update MANIFEST.in:

* remove .hgignore (was removed long ago)
* exclude all .pyc and .pyo files
Add a Readme-file for tests for how-to run tests.
For tests: change sys.path only if not running in a virtualenv.

Otherwise one would need to copy the tests/ directory to be able to
run the version actually installed in the virtualenv.
Fix test_multipackage* when running in virtual env.

In this case, archive_viewer is installed and can not be found in
`utils/...`. Use the installed script instead.
Fix typo.
Update .gitignore: ignore generated spec-files.
Fix: Stop processing if a file should be stored outside the dist-directory.

I discovered this case when building test-case basic/test_python_makefile
while in a virtual environment.

I decided to implement a hard stop, since PyInstaller must never ever
write outside the dist-directory. Otherwise an attacker could overwrite
arbitrary files. This is the classic file traversal vulnerability.

Still todo: fix the test-case basic/test_python_makefile to put the
file at the correct place.
Print filename which should be stored outside the dist-directory.
When including the Makefile, test for existence, not for platform.

Other platform but Windows may miss the Makefile, too. And it may
appear in Windows some when.
Fix basic/test_python_makefile: config.h was not found when in virtualenv.

Reason was: In virtualenv, _CONFIG_H and _MAKEFILE may have same or
different prefixes, depending on the version of virtualenv. But the hook
always used the same prefix for both.
Clean: remove unused imports.
Clean: Move basic/test_python_makefile.py to libraries/.

According to the README, as it tests a hook, not a basic function.
Use module `imp` for importing hooks.

This is required really detect if a hook does not exist, by catching the
ImportError. Up to now, an AttributeErrors was catched, and I was trapped
by this as my hook existed, but raised an AttributeError.
Add hook and test for std.-module `sysconfig` (new in Python 2.7, 3.2).
Fix: Run test_sysconfig only, if sysconfig module is available.
Fix missing import in hook-sysconfig.py
Add 'compat.venv_real_prefix'.

This takes the burden of distinguishing between virtualenv and
PEP 405 venv from the other parts of the code.
Use 'compat.venv_real_prefix' in other code-parts.
Fix: Hooks fail to relative import hookutils.

This was caused by not passing the package-name to imp.load_module().