Adds a pre-commit hook for detecting and replacing
occurrences of `g_malloc()` and `wmem_alloc()` with
`g_new()` and `wmem_new()`, to improve the
readability of Wireshark's code, and
occurrences of
`g_malloc(sizeof(struct myobj) * foo)`
with
`g_new(struct myobj, foo)`
to prevent integer overflows
Also fixes all existing occurrences across
the codebase.
e16166a74c