New Mathemagix keyword 'assuming'

Upgrade to version 2.1.2

Fix extremely annoying bug introduced by Jeroen Wouters' patch

Upgrade to version 2.1

Upgrade to version 1.99.21

Upgrade to version 1.99.20

Upgrade to version 1.99.19

Upgrade to version 1.99.18

Upgrade to version 1.99.17

Further fix