Added functions to report version information.

git revision and tags are gathered at compile time.
The included cmake modules will force a re-configure (a rerun of cmake)
before a build every time the HEAD commit changes. This means that we
don't need to remember to rerun cmake manually to fix the revision
number.
This also means that version.c is compiled everytime.

New functions:
- rapp_get_version: returns the current version, i.e. 0.1
- rapp_get_version_sha1: returns the git sha1 of the commit
- rapp_get_version_tag : returns the git tag (if any)
- rapp_get_version_full: returns $version.$revision
Check for return value of http_request_append_data only when needed.
Merge pull request #2 from gbagnoli/feature/version

Added functions to report version information.
No version on develop, it will be bumped in release branches.
http_request_get_method returns and HTTPMethod enum value.
tcp_connection_sendfile now knows only about file descriptor, the stat stuff was moved into http_response_writer_sendfile.
Test tcp_connection_sendfile.
Added tests for HTTPResponseWriter.
add the skeleton of the container test.

also add the dl* stubs needed by this test.
They are in a separate file make it possible to link it only
where needed.
coding style requires <obj>_new, not <obj>_open
typos (nitpicks)
bootrstrap the container tests

add more testing infrastructure; now we should have all that's needed.
Ensure to opened file.
more container tests.

first wupe done! coverate >= 90%! woot!
Fixed log line at startup.
nitpicks
use static libs to near zero compilation duration.

WIP, because the current implementation broke the coverage report.
Investigating.
fix compiler/linker flags

restore dynamic export and coverage support.
Merge branch 'feature/staticlib' into develop
implement the null container

the null container is a bundled, always available container
useful for debug purposes and/or as fallback emergency container.
Currently it just logs the requests it receives.