Deletes code conditional on unused defines
  - SINGLE_FILE_GENERATOR
  - NOT_YET_NEEDED
  - BETA2
  - IMPLEMENT_IVSPERSISTHIERARCHYITEM2
  - IVsOutliningCapableLanguage
  - CUT
  - DISABLED
  - OLDCODE
  - Suggestion4299
  - UNUSED_DEPENDENT_FILES
  - UNUSED_NESTED_PROJECTS
  - NEVER
  - false
  - UNUSED

closes https://github.com/Microsoft/visualfsharp/pull/353

commit 2839aab40f4e3ab434f0738d5c8e3691d7c2c5df
Author: latkin <latkin@microsoft.com>
Date:   Mon Aug 3 17:22:20 2015 -0700

    Fix merge conflict

commit fc4602bf8b60204d85e707db1438f78cc082cb3d
Author: enricosada <enrico@sada.io>
Date:   Thu Apr 9 18:15:19 2015 +0200

    remove SINGLE_FILE_GENERATOR

commit 2dc0802e76006c6f5dcceae3360325eba01aea6c
Author: enricosada <enrico@sada.io>
Date:   Thu Apr 9 18:08:21 2015 +0200

    remove NOT_YET_NEEDED

commit df49b75211747dcd4e0ff887ef4473a280bf4a59
Author: enricosada <enrico@sada.io>
Date:   Thu Apr 9 18:05:56 2015 +0200

    remove BETA2

commit 70858f0689b29638ebfb35e1c3b0aa149895b801
Author: enricosada <enrico@sada.io>
Date:   Thu Apr 9 18:05:36 2015 +0200

    remove IMPLEMENT_IVSPERSISTHIERARCHYITEM2

commit d5ec2047ed550db9396892bfbdea28b07bc46193
Author: enricosada <enrico@sada.io>
Date:   Thu Apr 9 18:02:21 2015 +0200

    remove IVsOutliningCapableLanguage

commit 7f78d984171b4ed22da6339c6b799bbd44e743b3
Author: enricosada <enrico@sada.io>
Date:   Thu Apr 9 17:55:24 2015 +0200

    remove CUT

commit d781a86012e497dd81fe811250d5efb481c80945
Author: enricosada <enrico@sada.io>
Date:   Thu Apr 9 17:54:59 2015 +0200

    remove DISABLED

commit d19d387bd38a0b60e688fe6fa40a24d539d5853d
Author: enricosada <enrico@sada.io>
Date:   Thu Apr 9 17:50:06 2015 +0200

    remove OLDCODE

commit 1997a739aa040aa06428f2d225f7d8771b27f938
Author: enricosada <enrico@sada.io>
Date:   Thu Apr 9 17:48:02 2015 +0200

    remove Suggestion4299

commit 58cfe73fd9931dfb0276be146dc8d51c04c68c51
Author: enricosada <enrico@sada.io>
Date:   Thu Apr 9 17:31:29 2015 +0200

    remove UNUSED_DEPENDENT_FILES

commit 790e49786bb74b1c7a3915ed4b4aaf6243543803
Author: enricosada <enrico@sada.io>
Date:   Thu Apr 9 17:19:47 2015 +0200

    remove UNUSED_NESTED_PROJECTS

commit b738f464175e825dad7abdc55ad0e0e20a36545c
Author: enricosada <enrico@sada.io>
Date:   Thu Apr 9 17:01:08 2015 +0200

    remove NEVER

commit 1f9dea77c2618eeaadec25edced524d51c21b534
Author: enricosada <enrico@sada.io>
Date:   Thu Apr 9 16:59:43 2015 +0200

    remove false

commit e43fe145b73c81329c1af18744517bef7deb9da4
Author: enricosada <enrico@sada.io>
Date:   Thu Apr 9 16:57:27 2015 +0200

    remove UNUSED