Don't depend on Spencer-specific regexp syntax (/u and /U) any more in unrelated places
.  Bump http package to 2.8.6.
Don't call "ulimit" on cygwin: On Cygwin the stack size cannot be modified, and the reported stacksize is much lower than the real one.
Extend the public and private stub tables with dummy NULL entries, up to the size of the Tcl 8.6 stub tables. 
This makes it easier to debug extensions which use Tcl 8.5/8.6 features but (erroneously) are attempted to be loaded in Tcl 8.4.
Extend the public stub table with dummy NULL entries, up to the size of the Tcl 8.6 stub tables. 
This makes it easier to debug extensions which use Tcl 8.6 features but (erroneously) are attempted to be loaded in Tcl 8.5.
merge-mark. Hoping trunk is OK now, again ;-(
Restrict the stub library to only use Tcl_PkgRequireEx, Tcl_ResetResult	and Tcl_AppendResult, not any other function. 
This puts least restrictions on eventual Tcl 9 stubs re-organization, and it works on the widest range of Tcl versions.
merge trunk