strip trailing '/' from paths, this is later converted to '\' which
causes execution errors for obj_int_extract/yasm. vs10+ wasn't affected
by this issue, but make the same change for consistency.

gen_msvs_proj:
+ add missing '"' to obj_int_extract call
  unlike gen_msvs_vcproj, the block is duplicated
  missed in: 1e3d9b9e build/msvs: fix builds in source dirs with spaces

Change-Id: I76208e6cdc66dc5a0a7ffa8aa1edbefe31e4b130