get_providers and start_capability allow semantic

now ~get_providers has an `include_semantic` field
of type bool which allows you to get back
providers of semantic capabilities which redefine
the given interface

~start_capability can be given an interface and
a provider which implements a semantic interface
which redefines the given interface and it will
start it
added some test reliability
get_providers and start_capability allow semantic

now ~get_providers has an `include_semantic` field
of type bool which allows you to get back
providers of semantic capabilities which redefine
the given interface

~start_capability can be given an interface and
a provider which implements a semantic interface
which redefines the given interface and it will
start it
added some test reliability
adding basic example workspace which I am using to prototype a solution to this issue
fixup tests
gitignore update
added service call to get resolved (flattened) remappings for a running Interface or provider
improve test reliability
more test reliability
added tests/fixes for ~get_remappings
up timelimit for one of the tests
Merge pull request #30 from osrf/issue_30

let semantic interface providers serves as providers for normal interfaces