Test for cert bundle file on Fedora
Probe for Fedora certificate file

RHEL/CentOS/Fedora systems put a composite bundle file at
/etc/pki/tls/certs/ca-bundle.crt instead of the fully derived
directory in Debian/Ubuntu systems at /etc/ssl/certs. So switch on the
presence of /etc/pki/tls and load set the CA source as the bundle file
if Fedora and the directory if otherwise.

Closes #22
Merge branch 'fedora-ssl'
Use generalized Makefile
Factor common types out of http-streams

Move Hostname and Port aliases to Network.Http.Types.
Minor corrections to Makefile
Depend on http-common
Factor out Types and RequestBuilder to http-common
Add install target to Makefile
Bunp API version
Change to using Network.Http.Internal
Build code before documentation
Deprecate getRequestHeaders
Implement getHeadersFull
Move Headers to bottom of documentation
Import correct package from http-common
Merge branch 'extract-common'

Conflicts:
	Makefile
Document API version change in README

Closes #46.
Propegate rename from http-common