fixed important topography bug detected by Bernhard Schubert: longitude blocks were inverted in topography/bathymetry file
added JPEG pictures of new topography files with longitude bug fixed
changed transversly to transversely (there was a typo)
A handful of fixes and work-arounds.
added program to filter the STATIONS file to include stations located in a given region only
Significant re-work of Pyrized version (still in progress).
Reverted accidental change.
switched to new convention on Caltech's "pangu" cluster: /scratch/komatits/DATABASES_MPI
changed NTSTEP_BETWEEN_OUTPUT_INFO to 100
changed iaspei to iasp91
added models 1066a and ak135, and changed call structure of iasp91
The 'local-path' option is now called 'scratch-dir'.
Modified code to use less memory for large adjoint runs (large
meaning many adjoint sources and receivers and many processors). 
Changes involve:
*reading adjoint sources in in chunks
*writing seismograms out in chunks for adjoint runs (not storing the
 entire trace
*locating sources in chunks

Added parameter NTSTEP_BETWEEN_READ_ADJSRC to Par_file and NSOURCES_SUB 
to constants file.  The first controls the "chunk" size for adjoint 
sources (in number of timesteps) and the latter controls how many sources
to locate at the same time.  I set it to 1000, it should be a reasonable
number.  The "chunk" size for adjoint seismograms is controlled by the 
parameter NTSTEP_BETWEEN_OUTPUT_SEISMOS that was already in Par_file.
Fixing that I added a Par_file with non-standard options in last commit
model options updated:
------------
isotropic_prem
transversely_isotropic_prem
crust_2.0_plus_transversely_isotropic_prem 
iasp91
1066a 
ak135
s20rts
3D_anisotropic
3D_attenuation
-----------
Added 6 new stations to STATIONS file
moved DATA/oldstuff to UTILS and suppressed DATA/util
moved filter_station_list.f90 to UTILS
release of version 4.0:

 v. 4.0 David Michea and Dimitri Komatitsch, University of Pau, France, April 2007:
        new doubling brick in the mesh, new perfectly load-balanced mesh,
        more flexible routines for mesh design, one more doubling level
        at the bottom of the outer core, new inflated central cube
        with optimized shape, far fewer mesh files saved by the mesher.
Updated the Pyrization for v4.0 and Pythia v0.8.1.3b4; successful run.