Revert "Use the ?stable vim-bufferline v0.3"

This reverts commit 7bc7db301af9205b4619892937735fa0affa1420.
Revert "Check out the ?stable vim-airline v0.6"

This reverts commit 1021db5eda66dad026266f47cc5b48880b215b4f.
This seems unnecessary as line numbers are shown by default
Claim more space in the airlines
Updated bufferline rotation options
Revert "Claim more space in the airlines"

This reverts commit 192a0d4fa9ec41a9c70530dbb9e01cd41e796d79.
Revert "This seems unnecessary as line numbers are shown by default"

This reverts commit 2c644f3c79b26eb5b06d98e14549e58c7d341b39.
Use the tabline; no need for bufferline?
Use tabline instead of bufferline