Add basic fm_bot script
Add basic fm_bot script

This handles batching and things like figuring out "skps" means "all the
files under the directory skps", "gms" means "all the GMs linked into
fm", etc.

You can set up one job on the command line, or any number of them
with a -script file, e.g.

    ~/skia (fm-bot↑1|●1…) $ cat fm.script
    gms b=cpu w=foo/8888
    gms b=cpu w=foo/565  ct=565
    skps b=gl w=foo/msaa4-skps samples=4

Change-Id: I878c623bfc8673f04b4effa247bc850c0258a89b
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/204582
Reviewed-by: Brian Osman <794c0b5534edf5601d88e1d41975d0262da12894@google.com>

google/skia,google/skia,google/skia,aosp-mirror/platform_external_skia,HalCanary/skia-hc,rubenvb/skia,google/skia,rubenvb/skia,google/skia,aosp-mirror/platform_external_skia,rubenvb/skia,rubenvb/skia,HalCanary/skia-hc,aosp-mirror/platform_external_skia,aosp-mirror/platform_external_skia,rubenvb/skia,google/skia,aosp-mirror/platform_external_skia,aosp-mirror/platform_external_skia,rubenvb/skia,HalCanary/skia-hc,HalCanary/skia-hc,HalCanary/skia-hc,google/skia,aosp-mirror/platform_external_skia,rubenvb/skia,aosp-mirror/platform_external_skia,HalCanary/skia-hc,rubenvb/skia,rubenvb/skia,rubenvb/skia,google/skia,HalCanary/skia-hc,google/skia,HalCanary/skia-hc,HalCanary/skia-hc,google/skia,aosp-mirror/platform_external_skia,HalCanary/skia-hc,aosp-mirror/platform_external_skia