Use the double-secret iPtr->lookupNsPtr field to get post-enter-trace
re-resolutions of commands done in the right context for oo forwards.
added some test cases, based on bug report
Give (objc, objv) their own ride from enter to leave traces.
Revise GetCommandSource() to return a normal Tcl_Obj value.
Revised GetCommandSource() can (and thus should) return a normal zero
refcount value.
Arrange for both execution traces and [info frame] to get their pre-subst
source strings from a common routine, with care taken to reduce copying
by that routine.
merge trunk
Use a new flag value TCL_EVAL_SOURCE_IN_FRAME passed in by callers to
determine whether the pre-subst source information in a CmdFrame is to
be used.  This takes the place of numLevels cross checking, so that field
is removed.  Routines are consolidated as well.
Only schedule leave traces if enter traces complete successfully.
This avoids a memleak, and opens a data slot, so we can pass objc, objv
without the need to copy them into a list value.
Consolidate some helper routines.
Arrange for both execution traces and [info frame] to get their pre-subst
source strings from a common routine.
[a16752c252] Correct failure to call cmd deletion callbacks.
[a16752c252] Correct failure to call cmd deletion callbacks.
merge trunk
[3610404] Re-resolution of command after enter traces invalidate epoch.
Make sure context is such that correct resolution happens.
Add several tests to check consistency of stack traces.
The fix for [3610404] leads to a simplification in the implementation of
forward methods.
Make sure the errors raised by execution traces become errors raised by
the traced command, as documented.  Deletion of the traced command was
supressing that.
Make sure the errors raised by execution traces become errors raised by the
traced command, as documented. Deletion of the traced command was supressing
that.
rebase TIP [http://tip.tcl.tk/425|425] implementation