Fix #187: handle EINPROGRESS and EALREADY in sendfile driver

Thanks to Maas-Maarten Zeeman for reporting this.
Remove leftover io:format calls from ciphers config
Add SSL protocol_version configuration element

Add protocol_version configuration element to allow supported protocols for
SSL servers to be specified.

Also add a new unit test for protocol_version.
Fix FCGI worker when an error occures during the response streaming

When a FCGI server is called, the response can be streamed by the fcgi
worker. Because yaws_cgi:fcgi_get_output/1 exits on error, if the exception is
not catched, the client connection will wait for a quite long timeout to be
closed.
Prepare for yaws 1.99
Set file encoding for wiki application

Added encoding directive to correctly compile when configured with utf-8,
file applications/wiki/src/wiki.erl
Add documentation and templates for rebar releases

Add the rebar-templates directory and the files it contains to provide
rebar templates for creating Erlang releases that use Yaws. Add
www/rebar_release.yaws to provide documentation for using the templates and
creating releases.
Add yapp appup and c_src *.d files to .gitignore
Minor release tweak
Update build instructions

The build instructions now comply with Christopher's notes
at http://sourceforge.net/p/erlyaws/mailman/message/32571909/
Merge pull request #189 from zxq9/master

Update build instructions
Merge remote-tracking branch 'upstream/master'