Add errmsg to check_allocate abort message

[jimmielin]

Fixes #297

Following up from the tropopause_find PR I've updated check_allocate to take in errmsg and updated the tropopause_climo_read to use it and other places within SIMA. I did not update all instances of check_allocate, particularly those in dynamics and in cpl/nuopc as I was not sure if they were brought in externally or not.

If the optional errmsg argument is present a linebreak is added to the end of the abort message using the new_line intrinsic (Fortran 2003). Since errmsg in allocate is a F2003 feature I think this is safe to use? It can otherwise be removed, it's just used to make the output prettier.

This is what it looks like:

 ERROR: cam_thermo_init: Allocate of 'test(test)' failed with code 1. Memory highwater is     641.32 mb, current memory usage is      42.41 mb
Allocation failed with: Hello world this is not really a failure but just a test at /somewhere/CAM-SIMA/src/data/cam_thermo.F90:203

or an actual example made possible by a duplicate allocation...

 ERROR: cam_thermo_init: Allocate of 'kmcnd(pcols,pverp)--2test' failed with code 5014. Memory highwater is     641.35 mb, current memory usage is      43.08 mb
Allocation failed with: Attempt to allocate an allocated object at /somewhere/CAM-SIMA/src/data/cam_thermo.F90:207