Added new module for reporting the memory usage of the code.
It is contained in the file report_memory.f90
This is called from the main program, found in C2-Ray.F90
To avoid problems with the output of the initial conditions, phih_grid
should be set to zero after being allocated.
Fixed several bugs in this new version

1. The calls to heat_lookuptable did not test for the flux strength
of the source and did not correctly pass the sourcetype.

2. sourcetype was both a module variable and a local variable in
photo_lookuptable and heat_lookuptable. To avoid confusion, the
local variable is now renamed to table_type.

3. In function read_table, the residual array was called with i_subband2
whereas this should be i_subband.