Correct type checking of static calls to non static operations, fixes
#213
Remove the `nil` type from the parser, fixes #214
Some class invariants cause thread scheduling problems, fixes #216
Clean up threads properly with exit statements, fixes #218
Correction to traces running in VDM-RT, fixes #219
Suppress stderr output in CT tests, fixes #220
Correction to stopped thread handling, fixes #224
Correction for deadlocked CT test cases, fixes #225
Correction to type checking of nil returns, fixes #230
Allow breakpoints on class invariant expressions, fixes #236
Distinguish record tags and record types. See #243.
Incorrect detection of recursive functions with lambda expressions,
fixes #245
VDMUtil`seq_of_char2val fails with backslash quotes, fixes #247
VDM-SL traces fail when referencing state data, fixes 252
Merge commit 'ccb8922d70ac1e885d91de64de26bc9cb3548d62' into development