Switch to C99 boolean type
Use stdint types
Phase out g_new and g_free
gchar -> char
Phase out g_assert
Phase out semver_new_version constructor
Phase out major, minor and patch setters
Avoid useless copy
Add semver_new_metadata and semver_new_full constructors
Rewrite semver_valid_identifiers to not use glib and do fewer allocations
Use strtok_r in semver_cmp_identifiers
Cosmethic