tests: put test-treemanifest.t on a port diet test-treemanifest.t had introduced HGPORT3 and HGPORT4, which were improperly added to run-tests.py. It also was not using HGPORT1. This recycles HGPORT, and shifts everything into HGPORT1 + HGPORT2.

chg: pass sensitive command line flags to server We are going to make chgserver load repo config, remember what it is, and load repo config again to detect config change. This is the first step that passes config, repo, cwd options to server. Traceback is passed as well to cover errors before hitting chgserver.runcommand.

chg: use mallocx and reallocx in hgclient This patch simplifies the code a bit, and reduces the binary size a little.

chg: add utility functions mallocx, reallocx They are like malloc and realloc but will abort the program on error. A lot of places use {m,re}alloc and check their results. This patch can simplify them.