1. Fix index access costs for MERGE tables, set block_size=myisam_block_size/#underlying_tables
instead of 0 which it was before.
2. Make index scans on MERGE table to return records in (key_tuple, merge_table_rowid) order,
instead of just (key_tuple) order. This makes an index scan on MERGE table to be truly a ROR-scan
which is a requirement for index_merge union/intersection.
Speed up column-completion in 'mysql'
Don't use ISAM if HAVE_ISAM is not defined
A lot of fixes for the embedded version. All libraries are now included in libmysqld.a
Changed arguments to convert_dirname() to make it more general.
Renamed files in the 'merge' directory to all use a common prefix.
Don't compile both assembler and C functions on x86
