[phobos] auto tester changes

[Brad Roberts]

I've added 2 new builds, and renamed one:

  Renamed: Linux 64 -> Linux 32/64
  Added:   Linux 64/32
  Added:   Linux 64/64

The first number is the dmd binary, the second is the generated code.  For 
example, Linux 32/64 means that dmd was built as a 32 bit binary and the 
output of the compiler was 64 bits for druntime, phobos, and the dmd test 
suite.  The three linux/64 related builds are all occurring on the same 
machine, serially, so don't expect to see all the results coming out at 
the same time or terribly fast.

For added benefit of those with bad memories, such as myself from time to 
time, hover over the column headers to get the explanatory text.

All of the 32 bit builds remain as 32 bit dmd's with 32 bit code gen.
  
Technically there's more dimensions that could be tested, such as the 32 
bit build on a 32 bit linux box generating 64 bit output and moving it to 
a 64 bit box to test on.  But, well, I'll leave that for some other person 
to setup and maintain. :)

In the not terribly distant future, I hope to see us adding freebsd/64 and 
osx/64 builds, so the structure of the tester results page is going to 
have to change.. it can't survive adding 3 or 6 more columns (one year 
maybe even the 3 for win64 too).  So, give some thought to how it could 
look.  I'm considering the landing page just having a grid of the most 
recent build for each supported platform, no history.  A deeper page could 
have the history for each dimension.

Later,
Brad