(generateApplet, generateServlet): Remove fields. Instead use
	bits in langOptions.
	(generatingApplet, generatingServlet, sharedModuleDefs): New methods.
	* Language.java (parse): Set langOptions from options parameter.

	* Shell.java (compileSource): Pass PARSE_IMMEDIATE only to parse;
	don't pass PARSE_CURRENT_NAMES (which is part of PARSE_FOR_EVAL).
	* standard/define.java (scanForm): Only set CAN_WRITE if
	sharedModuleDefs(), not for all immediate compilations.
	* standard/require.java (importDefinitions):  Always make alias
	declarations private, regardless of Compilation#immediate.

	* test-load-require-1.scm: Add needed module-exports.
	* test-load-require-2.scm: Likewise.