add header and trailer in each source file

add standard copyright header
add vim hints trailer
add the source code decorator script

used in commit ab1f3cdf719fe6e8f7a8bce51edb37fb840cef3d
to decorate the source files.
add usage instructions for cdeco.py
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.
add and use the request dispatcher

the request dispatcher binds an URL against a container.
The binding policy is first fit: the first registered container
which matches a given route is selected and the search stops.
container_null unit tests; restore coverage
bootstrap the httprouter tests
realign/reorder struct RoutePack

we don't know still if this is speed-critical, however
this reordering is trivial and cannot harm.
extend container API for httprouter needs.

be more strict during container creation for allocation failures.
add function for create a static, custom container: will be needed
by httprouter tests.
reimplement null container in terms of new custom container API.
add the default container and port to new API.

a `default` container is a container which runs independently
from the route (aka by default, hence the name).
If and only if the container doesn't serve - currently implemented
as checking for not-success in container invocation, the usual
search by route, first fit, takes place.

default container is optional and not set by default.
If there isn't a default container, the routing is purely done
by route match, first fit.

a default route can be useful, for example, in the following
scenario:
- you have a bunch of static files in $DOCROOT
- AND your app is mounted on $DOCROOT

without the default container, you'll have, either
- to mount the app under $DOCROOT/something (route = /something)
  and mount a static file container under $DOCROOT/ (route = /)
- to play wih rewrite_rules

or others similar nasty workarounds.
Of course you still can do that or whatever tricks you want, but
at least now you have a choice.
rename the setter of the default container
more router tests

functions coverage is now 100%.
add fake constructor, for debug and testing

to build fake requests is needed by the httprouter tests.
header, trailer and fix a memleak.
add linking exception; mark the boundary of th API
merge with develop.
Merge branch 'feature/dispatcher' from github.com

and quie honestly I'm not really sure all of this
ever happened.