Log error if saving to $tmpconffile fails.
Match returncodes of main_fetch_and_apply_config() to main_request_config()
Do not write trailing zero byte to $tmpconffile
string_equals(): use memcmp(), instead of hand rolling the loop
string_equals() now returns bool
Convert string functions to use bool, instead of this "inverted int".
Convert fs_* functions from "inverted int" to bool.
main_tempsave_fetched_config(): use fs_writecontents() instead of reimplementing
Use string_ensurez() instead of string_putc() with a zero byte.
main_load_previous_config(): Use fs_read_file()
changelog: Added a couple of internal cleanups.
Some more convertion of string functions to use bool,
instead of this "inverted int".
fs_empty_dir(): output error reason on unlink failures
tinc_write_subnetupdown(): handle errors from symlink()
fs_cp_file(): use buffer on stack, instead of malloced
Fixed logic conversion error in fs_get_cwd() plus added some better error messages.
fs_cp_r(): output more error messages in case of failures