cpp: bin: Amend use of namespaces and relative includes

- Remove unnecessary top-level bin namespace
- Include bin directory in include path
- Don't use relative includes
cpp: showinf: Add copyright and licence boilerplate
cmake: Split up bin and lib subdirectories

This makes additions and changes to components less likely
to cause conflicts.
Merge pull request #1468 from rleigh-dundee/cpp-showinf-fixes

C++: binary build and showinf fixes
Update auto-generated documentation

Repository: openmicroscopy/bioformats
Already up-to-date.

Generated by BIOFORMATS-5.1-latest-docs-autogen#223 (http://ci.openmicroscopy.org/job/BIOFORMATS-5.1-latest-docs-autogen/223/)