* c-lang.c: Set case sensitivity on for c_language_defn,
cplus_language_defn, and asm_language_defn.
* ch-lang.c: Set case sensitivity on for chill_language_defn.
* f-lang.c: Set case sensivitity off for f_language_defn.
* jv-lang.c: Set case sensitivity on for java_language_defn.
* language.h: Add enum case_mode, case_sensitivity.
* language.c: Define case_mode, case_sensitivity. Set case
sensitivity on for unknown_language_defn, auto_language_defn,
and local_language_defn.
(show_case_command,set_case_command,set_case_str): New static func.
(set_type_range_case): New static func, replaces set_type_range ().
(set_language_command,set_type_command,set_range_command,set_language):
Call set_type_range_case ().
(language_info): Print case sensitivity setting.
(_initialize_language): Add set/show commands for 'case-sensitive'.
Set default case mode 'auto'. Set default language 'auto'.
* m2-lang.c: Set case sensitivity on for m2_language_defn.
* p-lang.c: Set case sensitivity on for pascal_language_defn.
* scm-lang.c: Set case sensitivity off for scm_language_defn.
* symtab.c (lookup_symbol): Downcase symbol name if case sensivitity
is off.
