cmLocalGenerator: Rename 'MAKEFILE' to 'MAKERULE'

Rename the internal enumeration value for converting paths destined
for use in Makefile rule syntax.
cmLocalGenerator: Fix AddBuildTargetRule object file path conversion

The object file list is constructed for a shell, not a Makefile rule.
cmDepends: Refactor object file path conversion

Delay conversion of the path to object files (on the left-hand side
of dependencies) until just before they are written.  Also do not
convert the format of paths written to the 'depend.internal' file.
This is consistent with the way the right-hand side of dependencies
are already handled.
cmGlobalVisualStudio7Generator: Remove unused variable
Merge topic 'refactor-makerule-path-conversion' into next

848fab95 cmGlobalVisualStudio7Generator: Remove unused variable
85cea8a7 cmDepends: Refactor object file path conversion
e7ee892b cmLocalGenerator: Fix AddBuildTargetRule object file path conversion
9f92a78b cmLocalGenerator: Rename 'MAKEFILE' to 'MAKERULE'