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.
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.)
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
GSE2/STA2: adjust some test files

They did not adhere to STA2 line definition (in latitude field, can not
be represented according to format given by manual)
need to update scan.png baseline image

one file now has network parsed from STA2, one new file in gse2 test
data.
image tests: higher tolerance for 3 tests on very old matplotlib

I checked all three, the axis box gets plotted slightly differently for them on matplotlib 1.1.1 but that's not our problem.
Merge pull request #641 from obspy/fix_gse2_sta2

STA2 header line of GSE2 files
Merge remote-tracking branch 'upstream/master' into stream_select_empty_values

Conflicts:
	CHANGELOG.txt
stream.select(component=..): only regard last character of channel code if it longer than 2 characters (+test)
Merge pull request #637 from megies/stream_select_empty_values

Stream.select() with empty values
earthworm: actually use timeout advertised for Client in docs
new decorator to mark unittest test routines as "skipped" in case of
network errors
use new network-error decorator on earthworm tests