patch 8.0.1092: terminal debugger can't evaluate expressions

Problem:    Terminal debugger can't evaluate expressions.
Solution:   Add :Evaluate and K.  Various other improvements.

patch 8.0.1091: test for <cexpr> fails without +balloon_eval feature

Problem:    Test for <cexpr> fails without +balloon_eval feature.
Solution:   Remove #ifdefs.

patch 8.0.1090: cannot get the text under the cursor like v:beval_text

Problem:    cannot get the text under the cursor like v:beval_text
Solution:   Add <cexpr>.

patch 8.0.1089: cannot get range count in user command

Problem:    Cannot get range count in user command.
Solution:   Add <range> argument.

patch 8.0.1088: occasional memory use after free

Problem:    Occasional memory use after free.
Solution:   Use the highlight table directly, don't keep a pointer.

patch 8.0.1087: Test_terminal_cwd is flaky

Problem:    Test_terminal_cwd is flaky. MS-Windows: term_start() "cwd"
            argument does not work.
Solution:   Wait for the condition to be true instead of using a sleep.
            Pass the directory to winpty.

patch 8.0.1086: can't build with GTK 3

Problem:    Can't build with GTK 3.
Solution:   Rename function argument. (Kazunobu Kuriyama)

patch 8.0.1085: terminal debugger can't set breakpoints

Problem:    The terminal debugger can't set breakpoints.
Solution:   Add :Break and :Delete commands.  Also commands for stepping
            through code.

patch 8.0.1084: GTK build has compiler warnings

Problem:    GTK build has compiler warnings. (Christian Brabandt)
Solution:   Get screen size with a different function. (Ken Takata, Yasuhiro
            Matsumoto)

patch 8.0.1083: leaking memory in input part of channel

Problem:    Leaking memory in input part of channel.
Solution:   Clear the input part of channel.  Free the entry. Move failing
            command test to a separate file to avoid bogus leak reports
            clouding tests that should not leak.