Fix indexing mixed strategy profile of strategic restriction

In Python, when indexing a mixed strategy profile in a strategic
restriction by a strategy, the index of the strategy on the original
unrestricted game was being used instead of the index on the
restriction.  This revision corrects this bug.
Add support for writing strategic restriction to .nfg files

Being able to write a strategic restriction to .nfg files is essential
for using the equilibrium computation tools.  This implements this for
the underlying C++ StrategySupport, and for the Python
StrategicRestriction concept.
Bug fix in tracing strategic QRE on non-full supports.

The calcuation of function evaluations and Jacobians in strategic
QRE were incorrect in the case when the strategy profile does not
have full support.

In addition to correcting this bug, this introduces an implementation
of a player relative to a strategy support, which matches in part the
interface to the general GamePlayerRep.  This anticipates the eventual
introduction of strategic restrictions of a game, which currently are
only implemented in Python.
Fix bug in reference counting pure strategy profiles.

PureStrategyProfile had been reimplemented as a std::auto_ptr to an
internal representation class.  This was not correct vis-a-vis how this
class is used, as assigning a profile to another profile is assumed
to have copy semantics.  With an auto_ptr, these assignments were instead
transfering the internal representation pointer, leading to null
pointer dereferencing errors.  This was primarily observed in the
graphical interface, when editing strategic games after adding
strategies, but could also be triggered elsewhere.
Update version number to 13.1.1.
Fix out-of-bounds memory write in deleting subtrees.

This corrects a regression introduced in commit 48139744.
In that commit, internal details of canonicalization and other
cached computations in game objects were hidden from external
view and handled automatically.

An unnoticed side effect of this caused an out-of-bounds write
in deleting subtrees recursively.  In doing the recursive delete,
the extensive game is re-canonicalized along the way.  However,
previously deleted children of a node were not being removed from
the list of children at the interim steps, and so the canonicalization
was attempting to re-number those (now invalid and therefore deleted)
nodes.
Various minor updates to documentation and website mainpage.
Updated ideas list.
Additional fix for deleting subtree of extensive game.

The patch commited in 44434841 was still not quite correct, as it
would leave some child nodes in the game tree.  This commit corrects
the logic.
Update required wxWidgets to at least 2.9.5.
Update friend declarations to conform to modern standards regarding default arguments.
Workaround for compile error in wxWidgets

The wxWidgets macro wxFinite calls isfinite; on recent C++ compilers
this raises an error, as the more proper call is std::isfinite.
This commit manually redefines this macro in the source files where
it is called; a less than elegant but probably essential solution.
Correct infinite loop when parsing savefile with unbalanced quotes.

A savefile which had unbalanced quotes in the last quotes field would
result in the parser entering an infinite loop.  This is now fixed.

Fixes issue #118.
Code tidiness updates for clang LLVM 5.1 on OS X 10.9.

This commit bundles a number of mostly minor revisions to the code
to deal with deprecations and compiler warnings which arise starting
with the LLVM 5.1 clang compiler on OS X 10.9.

Mostly these are simply removing unused variables.  There are a few
rewrites of casts in Pelican; as Pelican is so old and dubiously
written in the first place, there is no reason to believe this makes
Pelican any less reliable than it already is.
Allowing wxWidgets 2.8.12 again to make life easier for linux users using apt.
Update version number for release 13.1.2.