SERVER-11203 Reverting changes to time support code to work with negative time_t

Doing this correctly depends on SERVER-11273

Revert "SERVER-11174 Reference db of tool test rather than global db object"
This reverts commit d1c2ae72c4829ed77cb6b7fe42e486910483caff.

Revert "SERVER-11174 Skip tests of negative dates on windows"
This reverts commit 9fcdfeb195c42e91a49e37212a65fea624d71c13.

Revert "SERVER-11174 Skip test for date that cannot be stored on 32 bit systems"
This reverts commit fc3b552e788e027af40523173790a20f49b27ec5.

Revert "SERVER-6058 Fix time_support_test on systems with small time_t"
This reverts commit c1a09966ff05c42c184870715e7a7383d02c477d.

Revert "SERVER-6058 Factor out date to UTC handling code and use in mongoexport"
This reverts commit 0b19be208f91e70c683d60c22011cad14a9fa78c.