Match Ranges & Pricing: changing preset should be possible for PM only

If user log in with no PM rights (so only translator rights), and they open the match analysis and then try to switch to word-based or char-based OR they try to select a different pricing scheme, they are logged out immediately.

Also we have a serious confidentiality problem there: Currently each translator can switch the pricing schemes by himself. This means, each translator is able to see the prices, the other translators have.