Buffer overflow and format vulnerabilities in functions exposed without unsafe

ncurses exposes functions from the ncurses library which:

• Pass buffers without length to C functions that may write an arbitrary amount of
  data, leading to a buffer overflow. (instr, mvwinstr, etc)
• Passes rust &str to strings expecting C format arguments, allowing hostile
  input to execute a format string attack, which trivially allows writing
  arbitrary data to stack memory (functions in the printw family).