Infer the reader driver, no options required

This patch adds a StageFactory::inferReaderDriver() method that takes
only a filename, no options. The provided options were not used as part
of the inference process, so the base method should not required them.
The original inferReaderDriver(std::string, Options) has been updated to
call this new method.
Without reader type, infer from filename

Add logic in PipelineReader::parseElement_Reader to attempt to infer the
reader type from a filename provided in the options, in absence of a
explicit type.

Fixes #278.
Remove returns from BOOST_AUTO_TEST_CASEs

These returns are not needed for the tests to run properly, and their
inconsistent use could cause confusion down the road.

Fixes #337.
Merge pull request #338 from gadomski/issue/337-test-case-return

Remove returns from BOOST_AUTO_TEST_CASEs
Remove two-argument version of inferReaderDriver

Per discussion on 01c077cca37687e2c159796011de44fcc9dda068, the
two-argument version of StageFactory::inferReaderDriver does a bit too
much. This patch removes the two argument version, and updates all uses
to the new, one-argument version.

This does not change inferWriterDriver. That method does some meaningful
tweaking to the passed-in options, so its removal should be a seperate
commit (+pull request) IMO.
Split inferWriterDriver into two

Similar to #340, the 2-argument infer{Reader|Writer}Driver might try to
do too much by both modifying options and finding the correct driver.
This patch splits the inferWriterDriver into two pieces. The
inferWriterDriver part does just that, while a new method,
inferWriterOptionsChanges, modifies an options object based upon a given
filename.
Merge pull request #341 from gadomski/feature/split-infer-writer-driver

Split inferWriterDriver into two
Merge StageBase into Stage.
Merge pull request #344 from PDAL/no-stage-base

Merge StageBase into Stage.
add decimation option to pdal translate
Merge pull request #345 from chambbj/issues/43-pdal-translate-decimation

add decimation option to pdal translate for #43
remove user-specific config scripts into cmake/examples to clean up root directory #342
Merge pull request #342 from PDAL/issues/342-no-more-top-level-config.sh

Remove personal configuration scripts
a more straightforward way of setting the nitf writer options
Add icebridge reader.
Merge remote-tracking branch 'upstream/master' into hdf5
Updates for changes concurrent with this branch.
Merge branch 'master' into issue/278-infer-reader-type

Conflicts:
	src/StageFactory.cpp
Merge branch 'master' into feature/remove-two-arg-infer-reader

Conflicts:
	src/StageFactory.cpp
Added an HDF5 include guard around an icebridge include.