doc: tweak the 'proxy' documentation in conf_ref.rst
doc: fix a semantic error in cli_vs_yum's skip_if_unavailable doc.

Thanks Kamil Paral for finding this!
doc: using --setopt from CLI. (RhBug:1044981)
doc: cli_vs_yum: no 'Processing dependency' lines. (RhBug:1044999)
packaging: own the plugin directories.
New version: 0.4.10
build: 0.4.10-1
doc: faq: explain a 'check-update' oddity.
doc: typo in 1f180f8.
tests: use iniparse.compat instead of configparser.

Using iniparse.compat consistently everywhere saves us a bit of a py2/3 compat
issues (the module renamed between the versions), plus we have no reason to
assume the standard lib implementation is better. should this change
(i.e. someone measures the std lib is faster) we can drop iniparse in a blink of
an eye.
plugins: add basic support for reading in plugin config.
doc: faq: 'dnf update' vs 'yum update'.
refactor: cosmetic: imports in dnf.yum.config
fix: typo in CLI's search(). (RhBug:1048402)
cli: cosmetic: help text incorrectly mentioning Yum. (RhBug:1048719)
doc: document 'remove' alias for 'erase'. (RhBug:1048716)
doc: 'dnf provides' does not do extra filename heuristics. (RhBug:1048572)
packaging: bump the year.
doc: specify types of config options in conf_ref.rst.
apichange: plugins: turns out the pluginpath has to depend on py2/py3.

So put it where it most logically belong.