Simplify and improve Crummy::StandardRenderer

[blaknite]

I've made quite a few changes and improvements to Crummy. Most notably is a fix to a XSS bug that occurs if your crumb's name is derived from user-entered data. Adding html_safe to strings so liberally is bad.

In the process of making these changes I did drop the microdata support due to the spec being abandoned. I didn't have much need or desire to implement the new spec.

Here's a run-down of what has changed. Pick and choose as you wish.

• Replace local_global lambda with better options hash and merge
• Reduce arguments on crumb_to methods by passing options hash
• Rails convention is to html_escape unless explicitely stated by using html_safe so name is now always escaped. This fixes a gaping XSS vulnerability
• Common crumb_to logic moved to another method
• Normalized configuration option names
• Right-to-left crumbs now behave the same across all formats
• Passing :html hash to add_crumb now allows you to add any attributes you want. Default atrtributes can be set with the crumb_html configuration option.
• Common name of 'separator' when doing in-line configuration
• Cleaned up trailing whitespace
• Bumped version to 2.0.0 as these changes are not backwards compatible.
• Updated tests

[blaknite]

I finally come back and revisited this branch two years later because I'm still using the gem in quite a few projects. Currently what I have done has no support for microdata and some options are removed. I'll be patching it up to remove the regressions.

Tests currently pass locally for what I've done but there's a bundle issue on travis :(