tag 0.3 mainly for the libosmocore () vs (void) API fix

1. be5f2c7 update git URLs (git -> https) by Harald Welte · 2 years ago
2. b07caac configure: don't turn some warnings into errors by Oliver Smith · 2 years, 8 months ago
3. 91a98c0 configure.ac: set -std=gnu11 by Oliver Smith · 3 years, 5 months ago
4. bad3897 convert build system to autotools by Harald Welte · 4 years, 8 months ago