Protect all access of stack to make sure not going out of bounds

[mjdecker]

[jmaletic]

typeStack - checked. No unguarded accesses found (closed)

stereotypeStack - checked. No unguarded accesses found (closed)

elementStack - checked. (closed)
unguarded accesses at nameCollectorHandler.hpp 185, 401
Added guards to 185 and 401 to fix issue. In develop

scopeStack - checked.
unguarded accesses at nameCollectorHandler.hpp 407, 496, 538, 651
Need to this in conjunction with moving python to separate class. ISSUE #38