Miniscule Step

• The configure script now covers the case of Power PCs. Files for the power pc scenario have been added to src/cwb/config/platform; darwin-64 has been renamed to darwin-x86_64 as a matter of consistency #79.
• Warning "variable 'nr_targets' set but not used" for files newly reported by Apple clang version 14.0.3 (clang-1403.0.22.14.1) is addressed #83.
• Misleading indentation warning issued by clang-15 addressed #85.
• cwb_encode(), cwb_makeall(), cwb_huffcode() and cwb_compress_rdx() perform tilde expansion on filename provided by argument registry, avoiding a crash #84.