Added compiler debugging functions.

[reviewed by Lydia]

* Moved the debugging variety of stringLoc() from baseAST.cpp to view.cpp,
so it is together with shortLoc() and debugLoc() (see below).

* Added the following functions in view.cpp, for use while debugging:

- return a string location for the given BaseAST* or int id (using aid()):
   - stringLoc() - full path (moved from baseAST.cpp) stringLoc()
   - shortLoc()  - just the file name, for brevity
   - debugLoc()  - switches between the above with the new option
                   --debug-short-loc (on by default);
		   debugLoc() is used in some of the new functions below

- overloaded the following functions to allow passing either a BaseAST*
  or an int id (using aid()):
   - viewFlags()
   - list_view()
   - nprint_view()

- functions showing a SymbolMap or a Vec<Symbol*> or a Vec<FnSymbol*>
   - map_view()
   - vec_view()

  I overloaded these to take either a pointer to map/vec or a variable
  by "reference intent" - for convenience.

  I had to instantiate vec_view for particular instances of Vec (that I cared
  about) - otherwise they would not be available in the compiler executable.

- functions showing all FnSymbols with a given char* name
  or all calls to a given BaseAST* or int it

   - fnsWithName()
   - whocalls()

- print a summary of calls in 'callStack'
   - printCallStackCalls()

* Extended --html generation with the following features:

- links to the previous and next passes at the top of each pass/module page,

- ditto for each FnSymbol
  (I chose the particular characters for the links so they are visually
   clear, yet occupy little space)

- show AST id for each block, with the new option --html-print-block-ids
  (off by default - preserves the current behavior)

- added an environment variable for --html-user (CHPL_HTML_USER)

- allow user-specified location for CHPL_HOME in the generated html,
  via the new option --html-chpl-home
  (this is to avoid spurious diffs when comparing two HTML sets)

- make line wrapping optional, with the new option --html-wrap-lines
  (on by default - preserves the current behavior;
   when off, use horizontal scrolling in the browser instead)

All new options are in the "developer" category.


git-svn-id: http://svn.code.sf.net/p/chapel/code/trunk@21946 3a8e244f-b0f2-452b-bcba-4c88e055c3ca
Retiring test/parallel/begin/sungeun/capture.future.

[requested by Brad]

This feature request (capture for tasks) was implemented in r21940.

As a follow up to r21940, here are some early discussion notes
regarding this feature, from the being-removed .future:

---
Brad suggested that the existence of task private variables could make
the situation better/clearer.

Evaluating some of the begin block at task creation time opens up a
bit of a can of worms because there is a question of where to draw the
line (how much should be evaluated?).

Another option might be to go the style of XMT futures where any
non-global variables that are used in the block are required to be
"passed in".  This might allow us to get rid of the heap allocation
step we have now during the parallel pass.

The solution should probably apply to cobegins also.
---


git-svn-id: http://svn.code.sf.net/p/chapel/code/trunk@21947 3a8e244f-b0f2-452b-bcba-4c88e055c3ca