Updated runtime files.
updated for version 7.4a.045
Problem:    Configure does not always find the right library for Lua.  Missing
	    support for LuaJit.
Solution:   Improve the configure detection of Lua. (Hiroshi Shirosaki)
Added tag v7-4a-045 for changeset da95a7f1d5a8
updated for version 7.4a.046
Problem:    Can't build without mbyte feature.
Solution:   Add #ifdefs.
Added tag v7-4a-046 for changeset f0361e297d9c
Updated runtime files.
updated for version 7.4a.047
Problem:    Some comments are not so nice.
Solution:   Change the comments.
Added tag v7-4a-047 for changeset 8c6615a30951