lowercase caron positioning

[davelab6]

• [x] rcaron, its too far to the left, over the stem, should be more central
• [x] tcaron its too low, and touching the bar. it should be just on top (but without touching) the right side of the bar. it can be a bit smaller than the one used in d and l
• [x] ldot and Ldot could be better

[juandelperal]

Fixed, thanks @davelab6