Fix a bug in Commute (#8)

Patch from
  http://www.nikhef.nl/~form/forum/viewtopic.php?f=3&t=140
Fix "a strange problem" reported by Kostja

http://www.nikhef.nl/~form/forum/viewtopic.php?f=8&t=141

The problem was: when a stored expression appears in the RHS,
simp6token() calls GetTable(). GetTable() may extend AS.OldNumFactors
and AS.Oldvflags if there is no enough space, but it didn't copy the
previous contents of these buffers. As a result, the information in
these buffers are lost, and actually uninitialized. Next, if another
(non-stored) expression appears in the RHS, simp6token() checks
AS.Oldvflags[n] for the expression, but it has now an uninitialized
value and may cause the "Factorized expression in RHS in an expression
of more than one term" error depending on the memory content.

Solution: make GetTable() copy the original contents in the buffers when
the reallocation occurs.
Remove compilation warnings on gcc (Ubuntu 4.8.2-19ubuntu1)

"unused-result" warning for calling ftruncate() in Utruncate(). (#13)
NOTE: TruncateFile() is not called from anywhere.

"maybe-uninitialized" warning in PreRandom() on ParFORM.
Partially fix "make check"

Remove the code that was used for determining the OS, because newer
rubies warn the usage of deprecated Config. The information of the OS is
actually not used anywhere.

Fix the result for examples.rb:Sec_3_44_2. Now #write "%e" doesn't
output an extra blank line. (It was changed by 44cf65fbe0.)

NOTE: For automake >= 1.13, "serial-tests" option has to be added in
AM_INIT_AUTOMAKE in configure.ac:

  AM_INIT_AUTOMAKE([foreign 1.7 dist-bzip2 serial-tests])

otherwise "make check" causes errors (#13), while adding "serial-tests"
causes an error at running automake < 1.12.
Occurs() in if statement. QuadFortran. toupper_ tolower_ in prepro. isdefined.
Added Occurs() in f, quadfortran in format, isdefined in #if and toupper_ and tolower_ in macro definitions.
Make sure that there is no other stuff

Merge branch 'master' of https://github.com/vermaseren/form
Merge branch 'master' into sa

Conflicts:
	sources/optimize.cc
Set the ; in #write in a more sensible way for FORTRAN
update to pre.c with ; in %e %E in #write
Merge branch 'master' into sa
[doc] Fix a typesetting error caused by \verb

It also contains corrections to syntax lines of Delete, ExtraSymbols,
FactDollar, Factorize, NFactorize, NUnfactorize and Unfactorize.
the synchronization of optimize.cc was not correct
synchronization had lost the quadruple precision
Made the constants in double/quad fortran a bit more sane.
Write options in quadfortran were not correct. Improved small integers.
Merge branch 'master' into sa
Took out some debug code, printing numbers of operations
[build] Use the serial-tests option if automake >= 1.13

It resolves the "make check" issue of #13 in most cases.
Repaired a bug in if(occurs()==....);
Merge branch 'master' of https://github.com/vermaseren/form
Set the counting routine to topdown