Add U_s parameter for HMSFRs to kdist calculation

Add the U_s parameter from the Reid et al. (2014) rotation curve to the
kinematic distance computation.  This introduces a change of at most 0.2 kpc
in the derived heliocentric distance to objects, and in most places it is much
smaller.  This was added in response to a referee comment.

	modified:   conffiles/galactic_params.conf
	modified:   rot_curve/omni_vphys2vlsr.pro
	modified:   subroutines/omni_read_conffile_galactic.pro
Set U_s = 2.9 km/s (Reid et al. 2014)

Set the U_s parameter for kinematic distance computation = 2.9 km/s (equal to
the value in Reid et al. 2014; was set at 3.0 during code testing).

	modified:   conffiles/galactic_params.conf
Enhancement to plotting routine, cosmetic fix for KDIST DPDFs

Enhancement for the plotting routine omni_plot_dpdfs.pro to allow for user
choice in the look of the output.

Cosmetic fix for the subroutine in prob_kdist.pro which squashes the extraneous
probabilites for objects beyond the Solar Circle -- the otherwise-uniform
probability for sources with no dense gas vLSR was being modified by the
squasher.  This is of no consequence except for plotting of DPDFs with
omni_plot_dpdfs.pro, which can lead to some confusing plots.

	modified:   dpdf/prob_kdist.pro
	modified:   subroutines/omni_plot_dpdfs.pro
Fix peak-finding algorithm for GRS spectra.

Fix issue in omni_grs_maskspec.pro when multiple peaks in the spectrum are NOT
separated by a valley dipping below ancil.grs_ta.  Once regions above
ancil.grs_ta are identified, recompute the peak indices using the greater of
ancil.grs_ta or the (peak TA* / ancil.grs_ratio).

	modified:   subroutines/omni_grs_maskspec.pro
Add timestamp to "all done" message

Add timestamp to the "all done" message at the end of distance_omnibus.pro.
This is purely cosmetic, but may be helpful for knowing how long it took to run
this monster.

	modified:   distance_omnibus.pro
Correct fix for the "Big Island" problem in OMNI_GRS_MASKSPEC

Correct fix for the "Big Island" problem, which was attempted in the 09/17/14
fix.  Now, the routine identifies islands above the THRESHOLD value, then
analyzes each island for multiple summits (a la the Big Island of Hawaii).  In
this way, if one island has multiple summits, they will be analyzed
individually using the criteria for multiple peaks in the spectrum.

	modified:   subroutines/omni_grs_maskspec.pro
Fix typos in previous commit.

Fix typos (syntax errors) in previous commit to omni_grs_maskspec.pro.

 	modified:   subroutines/omni_grs_maskspec.pro
Further typo fixes to "Big Island" bugfix

Further fat-finger-syndrome fixes to omni_grs_maskspec.pro, plus addition of
Check_Math() calls to both omni_grs_maskspec.pro and omni_import_velocity.pro
to silence "Floating underflow" errors.

	modified:   create_local_files/omni_import_velocity.pro
	modified:   subroutines/omni_grs_maskspec.pro
Small fixes to clear out "underflow" messages

Addition of Check_Math() calls to clear out "underflow" messages.  Also,
adjusted the prob_parallax.pro parallax array to NOT start at zero, since the
corresponding distances (1/pxarr) should not include an infinite distance.

	modified:   distance_omnibus.pro
	modified:   dpdf/prob_parallax.pro
Merge branch 'master' into release