- make pow_expr a seperate rule with higher precedence than mult_expr
- rename eq_expr/eq2_expr to ord_expr/eq_expr
- match strict_real_p instead of real_p, otherwise '1 / 2' is 0.5 instead of 0
- rewrote parser to use boost.spirit instead of a hand-written parser
- refactored request loading into 'request' object
- added 'expr', a command-line tool to test the new parser
- some performance fixes for affunctions