Add mega-test config for Kenton's home machine.

This is currently passing.

mega-test-kenton-home.cfg

+linux-gcc-4.9      9752 ./super-test.sh tmpdir capnp-gcc-4.9 -j8 gcc-4.9
+linux-gcc          9754 ./super-test.sh tmpdir capnp-gcc -j8
+linux-clang-3.5    9889 ./super-test.sh tmpdir capnp-clang-3.5 -j8 compiler clang++-3.5
+linux-clang-5.0    9892 ./super-test.sh tmpdir capnp-clang-5.0 -j8 compiler clang++-5.0
+mac                7064 ./super-test.sh remote beat caffeinate
+cygwin             8500 ./super-test.sh remote Kenton@flashman

mega-test.cfg

-linux-gcc-4.9     10518 ./super-test.sh tmpdir capnp-gcc-4.9 gcc-4.9
-linux-gcc-4.8      9801 ./super-test.sh tmpdir capnp-gcc-4.8 gcc-4.8
-linux-clang       10616 ./super-test.sh tmpdir capnp-clang clang
-mac                7937 ./super-test.sh remote beat caffeinate
-cygwin             9050 ./super-test.sh remote Kenton@flashman
-exotic             5581 ./super-test.sh tmpdir exotic exotic