added support for custom build message in vs201x generator

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branch : CustomBuildMessages
added support for additional manifest files to vs201x actions

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branch : Manifests
use new vc2010.element method instead of _p function

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branch : CustomBuildMessages
removed wip code from another branch commited by mistake

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branch : CustomBuildMessages
used vc2010.element instead of _p for additional manifests

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branch : Manifests
fixed NoWarnings flag for vs201x generators

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branch : FixNoWarnings
merge latest revisions

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branch : Manifests
forgot to add test_manifest.lua to tests/premake5.lua and small fixes

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branch : Manifests
Merged in dcourtois/premake-dev/Manifests (pull request #64)

add additional manifests support for vs201x generators
Merged in dcourtois/premake-dev/CustomBuildMessages (pull request #62)

added support for custom build message in vs201x generator
Merged in dcourtois/premake-dev/FixNoWarnings (pull request #65)

fixed NoWarnings flag for vs201x generators