Bugfix for HTTP 1.0 streaming

Wrong branch of mochicow_request:respond called, resulting in bad match exception, as everything related to streaming contains in Body, which supposed to be an io_list in that branch.
It does work with 1.0, as TransferEncoding is still 'identity'.
Check for minimum erlang version in boss_rebar, R15 atm
Update boss_rebar.erl
Merge pull request #312 from tempaccounterl/patch-2

Check for minimum erlang version in boss_rebar, R15 atm
Merge pull request #311 from danikp/static_files

Static files
Fixed syntax issue that prevents applications from compiling.
Pretty EDoc
added web controllers to /doc page
fixed path in html and added missing files
created basic styles (based on subset of bootstrap rules)
Merge pull request #316 from danikp/pretty_edoc

Pretty EDoc
Merge pull request #315 from davidw/master

Fixed syntax issue that prevents applications from compiling.
prettify default error page
renamed boss_html_error_template.dtl to boss_html_errors_template.dtl
new boss_html_error_template.dtl handles single error called from process_error/5

on a way corrected path problem with issue #316, _base_url has been forgotten
more files
added CSS to error page with "parse errors"
added comment to boss_web_controller.erl to better understand and distinguish between two error pages
Merge pull request #318 from danikp/pretty_error

Pretty error
erlydtl can use js templates
additional case handling if base_url is defined, but empty.
solves problem with redirecting to anoer app described here
https://groups.google.com/forum/?fromgroups=#!topic/chicagoboss/LXR_TI6nZQk
updated doc to show 'js' controller return value
docs show all filetypes supported as DTL templates
WebSockets: callback arity fix for service handler

Related to the changes made in c1bdf0223c.
Merge pull request #321 from ztmr/master

WebSockets: callback arity fix for service handler
Merge pull request #327 from danikp/fix_app_redirect

additional case handling if base_url is defined, but empty.