* Add flake8 configuration

.flake8:
Add flake8 configuration that limits the line length to 120 chars and
outputs to flake8.txt

* Add flake8.txt to gitignore

.gitignore:
Add flake8.txt (flake8 output file) to ignore.

* Syntax fixes and cleanup for top-level wscript

wscript:
Fix syntax of wscript according to pep8 (but do not break long lines).
Remove unused imports and move all module level imports to the top of
the file.
Fix broken build target of IIO driver (source argument to
`create_driver_obj()` supplied an uninitialized variable).
Break lines at 120 chars.

* Fix common/wscript syntax

common/wscript:
Fix syntax problems, unneeded imports and break lines at 120 chars.

* Fix compat/alloca/wscript syntax

compat/alloca/wscript:
Fix compat/alloca/wscript syntax

* Fix compat/wscript syntax

compat/wscript:
Fix compat/wscript syntax

* Fix dbus/wscript syntax

dbus/wscript:
Fix syntax and break lintes at 120 chars.

* Fix example-clients/wscript syntax

example-clients/wscript:
Fix syntax and remove commented code.

* Fix tests/wscript syntax

tests/wscript:
Fix syntax and commented code.

* Fix tools/wscript syntax

tools/wscript:
Fix tools/wscript syntax.

* Add github workflow for linting wscripts

.github/workflows/lint.yml:
Add github workflow for linting wscripts using findutils and flake8.

* Fix project version extraction in CI

.github/workflows/build.yml:
Adapt the project version extraction in CI to the syntax changes in
the top-level wscript.

This commit introduces the skeleton needed to implement reusable
operating system compatibility modules. This skeleton can then be
extended with the actual compatibility modules that work around
operating system specifics.

For example this will be used to be able to compile files that use
alloca on Windows. Also it can be used to implement replacements for
functions that are missing on some systems.