Add in changes to dist.sh from r13838 that were not vetoed or likely not to cause a veto.
Add in changes to dist.sh from r13838 that were not vetoed or likely not to
cause a veto.

* dist.sh:
  Add in support for curl if wget is not available; Add -sign option to use
  PGP/GPG if available; Add -nodeps option to not error out if dependencies
  are missing; Delay error from not having dependencies until we need them;
  add a comment as to why we need pax and wget/curl (r13848); factor out
  installation of dependencies into a common shell function to eliminate
  duplicate code; use variables for fetching book PDF & HTML to allow
  curl/wget.


git-svn-id: f8a4e5e023278da1e04e203c7fe051e3c4285d88@853946 13f79535-47bb-0310-9956-ffa450edef68

YueLinHo/Subversion,wbond/subversion,wbond/subversion,YueLinHo/Subversion,YueLinHo/Subversion,wbond/subversion,wbond/subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,wbond/subversion,wbond/subversion,wbond/subversion