Use the Linux paths for everything that isn't a Mac or Windows

Specifically, FreeBSD. Assuming something POSIX-like if there is no
specific code for the target OS is a good idea in general, though.
Correct a comment about GetDataString safety
Remove unused MSVC project files for tstc4netio and netpuncher
Update dependencies list in the README

Also remove mention of PATH from windows installer section - CMake finds
makensis using the Registry when it isn't in the PATH.
allow for constructing just below surface

Useful for basements and maybe also other structures in the future.
removed unnecessary defcore Value entries

Completely unneeded for structures and many other objects.
added basement as a structure

A feature to be added is that it automatically attaches to existing structures.
Clean up deprecated headers and functions

"gdk_pixbuf_unref has been deprecated since version 2.0 and should not be
used in newly-written code. Use g_object_unref()."

sys/timeb.h isn't used anymore since 2005.
Fix typo in Crash.ocs scenario description
added basement to worlds' player knowledge
Let CMake determine the location of the targets to install
Finish DEBUGREC compile option removal

Except for the DEBUGREC_RECRUITMENT option available in C4Include.h
cmake: Use builtin support for .rc compilation on mingw

This requires CMake 2.8.4.
cmake: The netpuncher can use the Scheduler source files from libmisc
cmake: Use C++ compiler to check for X11/extensions/Xrandr.h and keysym.h

To do this, port the CHECK_INCLUDE_FILES macro from the CMake source to
C++. While at it, actually check for both headers instead of XLib.h alone.
cmake: Use C++ compiler to check for vasprintf and iconv
cmake: Link the execinfo library if necessary for execinfo.h
Fix Sound() from deleted context when sword is deleted in strike callback
fixed construction blocking for below surface structures
fixed structure energy bars