add failing test for Stream.select() with "empty" values
fix Stream.select() with "empty" values
add a test file for GSE2 with STA2 header

this comes from an independent source, the actual values were changed so
that the original data is not recognizable anymore but the positioning
in the STA2 header line is unchanged.
refactor ResourceIdentifier.resource_id (to be able to use decorators)
refactor ResourceIdentifier.resource_id to ResourceIdentifier.text,
deprecate old property
refactor ResourceIdentifier

Keep attributes text/prefix/uuid separate and decide via self.fixed how
the current text representation looks like.
For fixed case: return user set text
For non-fixed case: return prefix + current uuid hash

Also introduces the possibility to regenerate the hash part for
non-fixed resource identifiers (useful for the referred object to get a
new hash when the referred object changes)
Merge branch 'master' into resource_id_refactor

Conflicts:
	obspy/core/event.py
some more refactoring for resource identifier
Merge remote-tracking branch 'upstream/master' into resource_id_refactor

Conflicts:
	obspy/core/event.py
change from resource_id.text to resource_id.id
Merge remote-tracking branch 'upstream/master' into resource_id_refactor
correct one missed replacement in 5d2979774ece, correct a tested warning
Merge remote-tracking branch 'upstream/master' into fix_gse2_sta2
basics for reading/writing STA2 line in GSE2
@mbyt: theoretically correct computation for 99c5a978b105ff2a2b0 proposed by @jwassermann. no adaptions of tests necessary.

(the conjugate was computed for the wrong one of the two signals in the
cross spectrum, making a manual shift by 180 degree necessary.)
test travis on py2.6 too

travis: pip install obspy with `--no-deps` (all dependencies are
installed in "pre-install" section, avoids re-installing newer
scipy, see https://travis-ci.org/megies/obspy/jobs/13862500)

debug missing suds in travis

travis: properly install dependencies for py 2.6 test run

travis: try to fix installation of py 2.6 build dependencies of dependencies
fix syntax of #670 for python 2.6
some Py 2.6 unittest fixes
GSE2/STA2: adjust parsing of STA2 line

All fields up to the last two adhere to fixed format columns in all
files I've seen so far, so used fixed columns for parsing them.
GSE2/STA2: adjustments to parsing/compiling STA2 line