Fixes in construction menu

Almost all is translation fixes.
eccbfe10f6ed768ddedcfa0437e4e99fe7ca5cb8 fixes some weird bug. This bug related only to SDL version(and windows pseudo curses). Construction menu with bug:
![5458955](https://cloud.githubusercontent.com/assets/5244047/3004747/16f49e30-ddb8-11e3-87a3-494364f05f44.png)
This happend only with translated strings and only in SDL. I replaced utf8_substr() to cursorx_to_position and all become normal. I think utf8_substr() is somehow broken on SDL.

In 3e82870cc21b00dd537deeead687ee6ffa97a98b I changed position of "Press ';' to toggle unavailable constructions." message. It placed to last line. I think menu look's better now.