Remove external themes from MkDocs

This change removes the dependency on mkdocs-bootstrap and mkdocs-bootswatch.
It also updates all references in the code. The only remaining connection is
when a user specifies one of these themes but they are not installed they get
slightly helpful error.

requirements/project-min.txt

@@ -2,7 +2,5 @@ click==3.3
 Jinja2==2.7.1
 livereload==2.3.2
 Markdown==2.5
-mkdocs-bootstrap==0.1.1
-mkdocs-bootswatch==0.1.0
 PyYAML==3.10
 tornado==4.1

requirements/project.txt

@@ -2,7 +2,5 @@ click>=3.3
 Jinja2>=2.7.1
 livereload>=2.3.2
 Markdown>=2.5
-mkdocs-bootstrap>=0.1.1
-mkdocs-bootswatch>=0.1.0
 PyYAML>=3.10
 tornado>=4.1