VS: Refactor flag table lookup

In cmVisualStudio10TargetGenerator, convert the static functions
currently used to lookup the flag table for each tool into class
methods.  This avoids passing the this->LocalGenerator member and
gives the methods access to other information that may be useful
in the future.
VS: Fix vcxproj elements specifying binary output locations

Fix generation of OutDir, IntDir, TargetName, and TargetExt element
values to encode the values for XML.
VS: Fix vcxproj specification of empty output file extension

When a binary output file is to have no extension, the TargetExt
element in the vcxproj cannot be left empty because VS will choose
a default extension.  Instead use "." because the Windows filesystem
will treat that as an empty extension.
VS: Refactor internal generator factory logic

Consume the space before the platform name as soon as possible
instead of including it in the comparison.
VS: Remove always-true condition on compile options block

The cmVisualStudio10TargetGenerator::ComputeClOptions method is
only called when the target type compiles, so do not duplicate
that check in the implementation.
VS: Set some options directly instead of using flag map

Instead of passing /TC, /TP, and /STACK: as strings to be parsed through
the flag map, directly set the results in the options map.
VS: Re-order logic to group MS-tool-specific options together
VS: Factor MS-tool-specific vcxproj settings into helper

Factor a WriteMSToolConfigurationValues helper method out of the
cmVisualStudio10TargetGenerator::WriteProjectConfigurationValues method
to isolate the configuration settings specific to MS tools.
Help: Add notes for topic 'FindOpenGL-target'
Merge topic 'vs10-refactor' into next

1edaef39 VS: Factor MS-tool-specific vcxproj settings into helper
808f4b1f VS: Re-order logic to group MS-tool-specific options together
13e6d559 VS: Set some options directly instead of using flag map
8f4bdcc6 VS: Remove always-true condition on compile options block
eaa9f2f8 VS: Refactor internal generator factory logic
2b3e7b6f VS: Fix vcxproj specification of empty output file extension
39af06e7 VS: Fix vcxproj elements specifying binary output locations
ee329d54 VS: Refactor flag table lookup
Merge topic 'FindOpenGL-target' into next

4883813f Help: Add notes for topic 'FindOpenGL-target'