libcommon: Cleanup
Refactor|libcommon: Switched d_net.c, d_netcl.c, d_netsv.c, fi_lib.c, hu_automap.c to C++
Refactor|libcommon: Switched p_inventory.c, p_xg_line.c to C++
Refactor|libdoom: Switched d_refresh.c, m_cheat.c to C++
Refactor|libheretic: Switched h_refresh.c, in_lude.c, m_cheat.c to C++
Refactor|libcommon|GameRuleset: Began remodeling GameRuleset into a C++ class

A C wrapper API for accessing rule values is necessary because it is
not presently feasible to switch all the relevant source files to C++
due to the large amount of C-isms also present. All source files which
need write access to the game rules are now in C++, however.

Todo: Fix new compiler warnings output by GCC/clang since this latest
batch of C++ switches.
Fixed|libcommon: Various compiler warnings
Fixed|libcommon: Compiler warnings (missing initializer, unused var/arg)
Fixed|libheretic: Compiler warnings/errors (dup time symbol, missing initializers)
Fixed|libheretic: Compiler warnings (unused var/arg)
Fixed|libcommon: Compiler warnings (missing initializer)
Merge branch 'master' into savegame-refactor
Merge remote-tracking branch 'remotes/origin/master' into savegame-refactor
libcommon: Cleanup
libdoom|DoomV9GameStateReader|libheretic|HereticV13GameStateReader: Use current game rules as basis for interpreting vanilla savegames

Alert the user about this assumption so that they might act accordingly
(ideally, by ensuring the rules are configured compatibly with those in
effect at the time the vanilla savegame was made).
Console|SaveInfo: Improved output of 'inspectgamesave'

Include a breakdown of the game rules in the SaveInfo description.
Debug|libcommon: Adjusted level of savegame file open logging to XVERBOSE, cleanup
libcommon: Update info for savegame slots more intelligently

It is no longer necessary to update the SaveInfo for all the savegame
slots at once. Update only those slot(s) pertinent to current task.
libcommon|SaveInfo: Track status changes of saved game sessions in SaveInfo

SaveInfo now monitors the status of the saved game session internally
and notifies interested parties when it changes. Note that the saved
session file is not currently monitored, however. This means that one
must still prompt a manual updateFromFile().

Also, changes to the user description are similarly observable.
libhexen|ACS|Cleanup: Applied 'session' naming convention to ACScript