cloud_aws: ephemeral support
core: added --config=PATTERN switch for deploy/audit/verify

Allows targetting deploy, verify and audit commands to a specific
configs only.
core: added tagging support for files and dirs

Files and directories can be optionally labelled with tags
that can be used to perform verify/audit/deploy/show operations
over a subset of the deployable files.

If a file/dir has been tagged, it is not included by default to
verify/audit/deploy/show operations. Instead, it must be explicitly
targetted via the --tag=TAG switch.

Tags can be added with a new plugin add_file() method "tags" parameter:

  self.add_file(source_file, tags=["foo", "bar", ""])

An empty string in the tag list indicates that the file shall be
included in the operation also when no --tag=TAG argument has been
specified.
rcontrol_paramiko: use epoll() when available for remote commands

select() stops working in large environments due to its value(fd)<1024
limitation.
core: add-library sys.path handling fix

add-library needs to add the extra search paths to the beginning
of sys.path so that they override e.g. older versions already there.
Also removed the old path from sys.path that the new path is replacing.
cloud_libvirt: use the force when reverting

This should fix errors like:

"""revert requires force: Target device address type none does not
   match source pci"""
Merge remote-tracking branch 'github-saaros/misc-fixes'
poni: PEP8 whitespace fixes
cloud_libvirt: nicer error message when 'cloud.profile' is not set
cloud_libvirt: clean up error handling and string formatting
versioning: always use git describe --long for versions
rcontrol_paramiko: epoll is in `select`, not `socket`
Merge remote-tracking branch 'saaros/misc-fixes'

* saaros/misc-fixes:
  rcontrol_paramiko: epoll is in `select`, not `socket`
  versioning: always use git describe --long for versions
  cloud_libvirt: clean up error handling and string formatting
  cloud_libvirt: nicer error message when 'cloud.profile' is not set
  poni: PEP8 whitespace fixes