use fgets() results when reading .mesh files, plus language fixes #596

Job	Run time
mmg-debug / ci (ubuntu-20.04, on, off, on, off, int32_t)	1h 16m 57s
mmg-debug / ci (ubuntu-20.04, on, off, off, off, int32_t)	1h 41m 1s
mmg-debug / ci (ubuntu-20.04, off, off, on, off, int32_t)	1h 3m 9s
mmg-debug / ci (ubuntu-20.04, off, off, off, off, int32_t)	1h 15m 56s
mmg-debug / ci (macos-12, on, off, on, off, int32_t)	43m 25s
mmg-debug / ci (macos-12, on, off, off, off, int32_t)	1h 10m 18s
mmg-debug / ci (macos-12, off, off, on, off, int32_t)	34m 14s
mmg-debug / ci (macos-12, off, off, off, off, int32_t)	45m 14s
mmg-debug / ci (ubuntu-20.04, off, off, off, on, int32_t)	3m 33s
mmg-debug / ci (macos-12, off, off, off, on, int32_t)	6m 39s
mmg-debug / ci (ubuntu-20.04, off, on, on, off, int32_t)	1h 2m 13s
mmg-debug / ci (macos-12, off, on, on, off, int32_t)	35m 31s
mmg-debug / ci (windows-2022, off, off, off, off, int32_t)	54m 7s
mmg-debug / ci (windows-2022, on, off, off, off, int32_t)	53m 39s
mmg-debug / ci (windows-2022, off, on, off, off, int32_t)	1h 0m 2s
mmg-debug / ci (ubuntu-20.04, on, on, on, on, int64_t)	4m 13s
mmg-debug / ci (ubuntu-20.04, off, off, on, on, int64_t)	1h 13m 14s
mmg-debug / ci (ubuntu-20.04, off, off, off, off, int64_t)	2m 10s
mmg-debug / ci (macos-12, on, on, on, on, int64_t)	8m 1s
mmg-debug / ci (macos-12, off, off, off, off, int64_t)	4m 8s
mmg-debug / ci (windows-2022, on, on, off, off, int64_t)	4m 47s
mmg-debug / ci (windows-2022, off, off, off, off, int64_t)	4m 47s
mmg-debug / upload_coverage	2m 4s
	14h 49m 22s

Provide feedback