Took another pass through README.cray

I took another clarifying pass through README.cray, focusing on the
first half of the file.  In particular, I:

* divided the numbered instructions into sections for "building Chapel
  from open source" vs. "using a Chapel installation" to clarify those
  things that need to be done never or once vs. those which need to be
  done on every use.

* added some more preamble text about using Chapel on a Cray CS
  vs. X-series system

* fixed a bunch of the steps that were very X-series specific and
  didn't seem to refer to CS configurations at all.  For example, the
  former step about making sure a PrgEnv was loaded.

* Generally, re-alphabetized XC, XE, XK, XT in that order in part
  because it emphasizes the newer/more important systems first and in
  part because it's alphabetical.  We can wrestle more with what the
  proper order should be if/when the next machines is called XZ.

* Additional wordsmithing, whitespace, formatting, etc.



git-svn-id: http://svn.code.sf.net/p/chapel/code/trunk@22068 3a8e244f-b0f2-452b-bcba-4c88e055c3ca
Some more HDFS explanatory text from Tim related to multilocale setup



git-svn-id: http://svn.code.sf.net/p/chapel/code/trunk@22069 3a8e244f-b0f2-452b-bcba-4c88e055c3ca
Adding a few more missing cases

Vass caught a few more missing type cases from my argument intent
tables.  Submitting those on his behalf.



git-svn-id: http://svn.code.sf.net/p/chapel/code/trunk@22070 3a8e244f-b0f2-452b-bcba-4c88e055c3ca
Fixed a typo that I introduced in the previous commit

(Always compile your LaTeX before committing boys and girls)



git-svn-id: http://svn.code.sf.net/p/chapel/code/trunk@22071 3a8e244f-b0f2-452b-bcba-4c88e055c3ca