Removing transaction symbols from package namespace (2)

[marko-k0]

Fix #185. (I've created another branch with commit that carries changes from my initial commit and another commit that carries all the changes that I've missed).

[todofixthis]

Hey @redondo-mk sorry it's taking me so long to merge this in. Since this change breaks backwards-compatibility, I want to get the next minor release out first, and then we'll merge this for v2.1.