Compatibility fixes for Blender 2.78c

Blender 2.78c is shipped with a version of the io_blend_utils module that
doesn't have a `pythonpath()` function yet, and that's bundled with an
older version of BAM. To work around this, we ship BAM as wheel, and detect
whether this version is needed to run.

As an added bonus, Blender 2.78c can now also use the file exclude filter
for Flamenco. The `bam_supports_exclude_option()` function is thus no
longer necessary.

blender_cloud/blender.py

@@ -461,16 +461,7 @@ class BlenderCloudPreferences(AddonPreferences):
         path_box.prop(self, 'flamenco_job_output_path', text='')
         props = path_box.operator('flamenco.explore_file_path', text='', icon='DISK_DRIVE')
         props.path = self.flamenco_job_output_path
-
-        show_warning = bool(self.flamenco_exclude_filter and
-                            not bam_interface.bam_supports_exclude_option())
-        job_output_box.alert = show_warning
-        job_output_box.prop(self, 'flamenco_exclude_filter',
-                            icon='ERROR' if show_warning else 'NONE')
-        if show_warning:
-            job_output_box.label(
-                text='Warning, the exclusion filter requires a newer version of Blender!')
-        job_output_box.alert = False
+        job_output_box.prop(self, 'flamenco_exclude_filter')
 
         prop_split = job_output_box.split(0.32, align=True)
         prop_split.label('Strip Components:')