Barebones working code.  No different from Diecker v.2 except that it now works

The previous commit worked, but had VERSIONSWITCH added as well.  This
version has no additions from me.  This is the most basic working code
for TIMCOAT v.2
Baseline for moving onward now

Erroneous use of second RANDOM_NUMBER removed.
Added Timer to Basline
Added beginning of MSWITCH to baseline - 1

The new versionswitch has been renamed as MSWITCH for mode switch to
switch between the SiC corrosion and kernel migration model or neither
of those two.
Added Kernel Migration and Corrosion - 2
First block of MSWITCH added successfully

Gets same answer as baseline.
Previous commit "Added Kernel Migration and Corrosion -2" got 146 vs 145
for the baseline.
Second Block of MSWITCH added successfully
Additional MSWITCH blocks added - some bugs

Answer changed slightly, need to de bug now.
Revert "Additional MSWITCH blocks added - some bugs"

This reverts commit 2e549ce9e1e910532395fa4bd0c905a612281ccb.
Cleaned up formatting - beginning more MSWITCH
Problem at line 1690

If comment out DCORR=0.D0 and Write . . . then answer is same as all
previous runs.  But if leave them in, the answer is different.
Problem at Line 1690 - 2
Problem at Line ~1680

Depending on number of lines of code below the ELSE, the code gives
different numbers of failed particles and failed TRISO layers.
Added new math functions and modified code to use them
Changed to work in Linux file suffixes
Removed test WRITE commands near line 1690
Merge branch 'master' into jeremy