Improve `cider--goto-expression-start`

  - Use `backward-sexp` when at the end of the list-like structure
  - Use `syntax-ppss` instead of font-lock property
Don't use callback buffer in compilation error highlighting and navigation
Execute each response in process buffer

  Some responses might reset the buffer, leading to "not a hash-map(nil)" error.
Easier to understand how to set up dependencies
Merge pull request #863 from slipset/master

Easier to understand how to set up dependencies
Add the ability to jump to a definition from a docview buffer
Add missing empty line
Kill a trailing space
Kill some commented out code
gittip is now gratipay