Acceptance test segmentation fault

The test 00_basics/01_compiler/200.x.cf segfaults when running because of a static char array.
This commit replaces the char array with Buffer.
Auto resize for printf

Mikhail showed a way to copy a va_list, so it can be traversed more than once.
This allowed me to do auto resizing when in printf and vprintf.
Removing the manual resize of Buffer

Since Buffer can now auto resize itself even in Printf or VPrintf, I removed the previous manual increases.
Merge pull request #309 from cduclos/master

Avoiding segmentation fault on a test