telepathy-glib and telepathy-qt4 currently work around old CMs by assuming that parameters matching /(^|-)password$/ are passwords, and hence should have the SECRET flag.
They shouldn't need to do this; the SECRET flag has existed since telepathy-spec 0.17.2 and telepathy-glib 0.7.5.
As a bonus, I also fixed some configure.ac trivia in the referenced branch.
I assume your branch is now: http://git.collabora.co.uk/?p=user/smcv/idle-smcv.git;a=shortlog;h=refs/heads/secret
Looks good to me but you can drop this patch: http://git.collabora.co.uk/?p=user/smcv/idle-smcv.git;a=commitdiff;h=bb9df367e74b4c04ce60d80fc3d66e3a45a44492
I cherry-picked the 2 relevant commits. Will be in 0.1.6