Test demonstrating need for "adjust" manipulation in TclSubstTokens.
[d614d63989] Ensure that there are no trailing colons as that causes chaos when a deleteProc is specified.
Workaround for [http://sourceforge.net/p/mingw/bugs/2065/|MinGW bug #2065]. 
Both MinGW and MinGW-w64 (32-bit) are affected. 
Even though Win64 is not affected, adding -static-libgcc doesn't harm there, and we don't want to distrubute additional dll's with MinGW-compiled Tcl anyway.
Cherrypick [87d1313df3] from trunk: 
Workaround for [http://sourceforge.net/p/mingw/bugs/2065/|MinGW bug #2065]. 
Both MinGW and MinGW-w64 (32-bit) are affected. 
Even though Win64 is not affected, adding -static-libgcc doesn't harm there, and we don't want to distrubute additional dll's with MinGW-compiled Tcl anyway.
[219226]: Rewrote how ::env is synchronized to the environment so it no longer
smashes the array or its elements flat, This affects traces on env, links to
env, and iterations over env: it makes them work as naïvely expected.
Merge forward new test, marked as knownBug, so other merges are no longer held back.
merge 8.5
Fix test source-4.1
merge trunk