base_path attribute accepts Proc

Added small description on the base_path that says the newcomer he can use a proc on the base_path attribute
Use GitHub Flavored Markdown for parsing the markdown
Merge pull request #84 from MongoHQ/gfm

Use GitHub Flavored Markdown for parsing the markdown
more flexible Entity
DRYing the entity name parsing
Merge branch 'pr/83'
Follow 1.2 specs more precisely.
Merge branch 'pr/82'
Merge pull request #78 from apaganobeleno/patch-1

readme update: base_path attribute accepts Proc
support defaultValue on params and headers
When no default value given, also don't put it in the json.
Merge branch 'pr/77'
Add dataType to the params output
Update spec for datatype and add in headers.
Merge branch 'pr/79'
if base_path is relative make it absolute using request.base_uri
Merge branch 'pr/69'
Adding support for form parameters for PUT and PATCH method types
Merge branch 'pr/55'
Don't lock grape-entity version