Replacing GPL spline code by LGPL spline code

Now using the LGPL SPLINE library
http://people.sc.fsu.edu/~jburkardt/c_src/spline/spline.html

Adding an extra test, as the current obspy tests do not seem
to cover the interpolation part.

See #827.
pep8
typos and py3k
x axis inputs must be strictly increasing

thx to @QuLogic for pointing that out
beautifying
Merge pull request #892 from mbyt/SPLINE

Replacing GPL spline code by LGPL spline code
docstrings
fix a bug introduced in 6a914e66d02, see #903
add degrees2kilometers helper routine (inverse of already existing
kilometers2degrees) + basic test
Setting manually timing_quality in the Trace.stats.mseed.data_quality
optional attribute
Renamed buffer to bfrNp and added blockette nb to handle timing_quality
Add read support for timing quality, add blkt number in writing, add
set_flags_in_fixed_header
Add test cases and reuse of the details arg in readMSEED
Changes suggested by @krischer and @QuLogic
# This is a combination of 2 commits.
# The first commit's message is:

improving regressions from attribdict to segy

# This is the 2nd commit message:

quality improvements
Quality and unittests improvements
Attempt to repair butchered history
Minor corrections suggested by @QuLogic
Merge pull request #855 from sfieux/issue855

MiniSEED Activity Flag implementation
Fix spelling of reproducible.