Support for adding to an associative array's domain via the array itself
A small test to demonstrate adding to an associative domain via the array
A more deterministic test to ensure that the backing domain contains the indices we implicitly added
Removing comments that will end up in associative primer
Fixing a race condition between dsiAccess and dsiAdd
A small test to stress parallel implicit key adds
Merge branch 'master' of github.com:chapel-lang/chapel into assocImplicitAdd
Fixing deadlock when attempting to remove an index from the domain
Moving clearEntry back to dsiRemove
Improving parSafeAdd
Merge pull request #128 from benharsh/assocImplicitAdd

This code allows for one to implicitly add to an associative array's domain via that array. This makes associative arrays a little more pleasant to work with.

Before:

myDom += newKey;
myArr[newKey] = foo;

After:

myArr[newKey] = foo; // newKey added to backing domain if not present.

An important restriction is that the array and domain must share a 1:1 relationship. More simply, the domain must be backing only one array. The motivation for this restriction is that it may be surprising that other arrays' index sets are modified when it appears that we are only modifying one array. If this restriction is violated, the program will halt.

An 'out of bounds' halt will still occur if attempting to read from a bad index:

Before and after:

writeln(myArr[badKey]); // if 'badKey' is not in myArr's index set, the usual error will be encountered.

A number of additional changes have been made to prevent race conditions and deadlocks how that we can modify the index set in parallel.