update tbse comments

tbse

@@ -4,7 +4,8 @@
 #
 # Run script to Test Binary(_c) Sellar Evolution: tbse
 #
-# This script (usually) runs one stellar system, i.e. a single or binary star.
+# This script (usually) runs one stellar system, i.e. a single or binary star,
+# using binary_c.
 #
 # If you want to evolve a stellar population, use the binary_grid2
 # scripts (in src/perl/scripts-flexigrid2) or a newline-separated list of
@@ -12,24 +13,26 @@
 #
 # >> You SHOULD NOT try to run many stars using tbse-like scripts! <<
 #
-# Full documentation is in the doc/ directory
+# Full binary_c documentation is in the doc/ directory or online at
+# http://personal.ph.surrey.ac.uk/~ri0005/doc/binary_c/binary_c.html
 #
+################################################################################
 #
 # To make this script work change the variables below which are given as
 #
 # VARIABLE=<value>
 #
 # Note that the value can be a macro name instead of an actual number,
-# and that "True" and "False" (and similar, e.g. "T", "F") are mapped
-# to 1 and 0, as you would expect.
+# and that "True" and "False" (and similar, e.g. "T", "true", "F") are 
+# mapped as one might expect.
 #
 # These values are passed to the binary_c executable and the results sent to 
 # stdout (usually your terminal, although see the "internal_buffering"
 # section for output options).
 #
-# There are other options, e.g. debug, echo(lines), valgrind, gprof, gcov,
-# bug, etc.
-# details of which are in the binary_c documentation.
+# There are many flags which can be given to tbse, e.g.
+# debug, echo(lines), valgrind, gprof, gcov, bug, etc.
+# details of which are in the binary_c documentation and/or below.
 #
 # Often the BSE model is referred to, this is the MNRAS paper of Hurley et
 # al. (2002) and/or Hurley et al. (2000) - see the doc/papers directory.
@@ -51,7 +54,7 @@ alias ENDCOMMENT="fi"
 set -o pipefail
 ulimit -s unlimited
 
-# save IFS
+# save IFS (internal field separator of the shell)
 IFS_ORIG=$IFS
 
 # activate extra logging?