Rmove two redundant indent
cls: set \bibsep to 0pt
cls: fix graphicspath

In grfguide.pdf, the path should be "A list of directories, each in a {}
group (even if there is only one in the list)".
Merge pull request #121 from grissiom/misc-fix

cls: fix graphicspath

Thx @grissiom for making BUAAthesis better！
Merge pull request #120 from huxuan/bibsep

Set bibsep to 0pt & some code clean, fixed #118