Update comparison example in include for ST_Buffer and ST_MakeEllipse
Add description and images for ST_Buffer
Update ST_Buffer with the new parameter

Conflicts:

	docs/dev/ST_Buffer.md
Merge remote-tracking branch 'upstream/gh-pages' into buffer_with_parameter
Merge remote-tracking branch 'upstream/gh-pages' into st_makellipse_buffer
Update description and images for ST_Buffer
Update images for ST_Buffer
Update description for ST_Buffer
Merge remote-tracking branch 'mireille/st_makellipse_buffer' into gh-pages
Corrections for @mlecoeuvre