schemas: allow genshi elements inside Path tags

This is particularly useful for Augeas commands.
Cfg: let EncryptedGenerator load setup object whenever the plugin is imported

Previously, if CfgEncryptedGenerator was imported before the Cfg
object was instantiated, it would finalize the
Bcfg2.Server.Plugins.Cfg.SETUP object with a value of None, and would
be unable to access the options dict.
XMLSrc: Load XML in one step instead of separate read and parse
bcfg2-lint: New TemplateAbuse plugin detects templated scripts

TemplateAbuse detects templated scripts (either files that end with a
known extension, or that start with a shebang line) and executables
(based off of their permissions in info.xml) and warns about them,
since templating scripts is dicey at best, and almost always better
done by templating a config file for the script to read instead.
bcfg2-lint: New ValidateJSON plugin

This plugin validates the JSON files that can be used by Properties
and Ohai.
testsuite: made pylint tests at least kinda work with pylint 1.0

They still don't pass, partially due to what appear to be bugs in
pylint and partially due to a few new things that pylint is checking
for in 1.0, but we don't use pylint 1.0 in travis-ci so i'm not
terribly worried about that right now.