VS script: Handle variation among configurations
VS script: Handle variation among configurations

The script now emits a meta-solution that include all projects across
all configurations. For example, third party libraries may not be in
all configurations, or certain targets are only present in some.

Additionally, the ItemDefinitionGroup (which includes preprocessor
definitions) is included from every configuration's project file, so
syntax highlighting of inactive code works correctly.

BUG=skia:

GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=5085

Change-Id: I241d83aea3f076365811965161fc941f82c9714c
Reviewed-on: https://skia-review.googlesource.com/5085
Reviewed-by: Greg Daniel <39df0a804564ccb6cf75f18db79653821f37c1c5@google.com>
Reviewed-by: Cary Clark <52792aa984ff6c4e9c802c7fa3093ed6a52a791f@google.com>
Commit-Queue: Brian Osman <794c0b5534edf5601d88e1d41975d0262da12894@google.com>

rubenvb/skia,aosp-mirror/platform_external_skia,aosp-mirror/platform_external_skia,Hikari-no-Tenshi/android_external_skia,google/skia,rubenvb/skia,Hikari-no-Tenshi/android_external_skia,rubenvb/skia,rubenvb/skia,Hikari-no-Tenshi/android_external_skia,rubenvb/skia,Hikari-no-Tenshi/android_external_skia,aosp-mirror/platform_external_skia,aosp-mirror/platform_external_skia,HalCanary/skia-hc,aosp-mirror/platform_external_skia,aosp-mirror/platform_external_skia,Hikari-no-Tenshi/android_external_skia,rubenvb/skia,google/skia,google/skia,HalCanary/skia-hc,google/skia,google/skia,google/skia,aosp-mirror/platform_external_skia,aosp-mirror/platform_external_skia,Hikari-no-Tenshi/android_external_skia,google/skia,google/skia,HalCanary/skia-hc,HalCanary/skia-hc,aosp-mirror/platform_external_skia,HalCanary/skia-hc,rubenvb/skia,HalCanary/skia-hc,HalCanary/skia-hc,HalCanary/skia-hc,google/skia,Hikari-no-Tenshi/android_external_skia,google/skia,rubenvb/skia,HalCanary/skia-hc,rubenvb/skia,aosp-mirror/platform_external_skia,rubenvb/skia,HalCanary/skia-hc,Hikari-no-Tenshi/android_external_skia