Fix cleaning after tests
Add new redirecting context managers
Use new redirector for Dopri/Radau building

Full output from distutils redirected to file `build.log` in appropriate
temporary directory.

While here, simplify a lot `try/except` block
Use new redirector for module 'utils'
Use new redirector for Auto building

Full output from distutils redirected to file `auto.log` in appropriate
temporary directory.

While here, simplify a lot `try/except` block and fix formatting
Use new redirector in toolboxes
Remove old redirector
Remove 'fixedpickle' module

Resolves #75
Merge pull request #77 from z2v/feature/75-remove-fixedpickle

Remove 'fixedpickle' module
Merge pull request #76 from z2v/feature/30-replace-redirector

Use new output redirectors for stdout/stderr