Refix #293. Only replace the left angle bracket of '<xxx-xxx>' style.

Shougo,
I refix #293. Only replace the left angle bracket of `'<xxx-xxx>'` style. No left angle bracket repacement for `<Leader>`, `<Space>`, etc, so the non-`<xxx-xxx>` style works out fine in 'mapppings' option now.

Thanks & Best Regards,
liangfeng