some char widths differ between vte and glibc wcwidth
I saw this konsole bug concerning the wcwidth values of U+4DC0..U+4DFF. Testing shows that vte is also affected by the same problem, with the same symptoms. Looking at glibc source for wcwidth data even shows that apart from the block above glibc has a few more cases where their wcwidth differs from the unicode data.
We should consider to use the glibc values here.