make it possible to specify font size in percent

Ignore-this: 41793a20463100960f64d0f3631a489

darcs-hash:20140910153942-fae1a-cf92790f34256c936445e5f56f7fccfe77114bec
slight code simplification

Ignore-this: 2336e82bbacf273bde3af331f636a68

darcs-hash:20140910183625-fae1a-58d33eb2f47fa46c9c7e2cf4d47d2eadee9c2001
fix a problem with the position of underlines, when there is no shadow

Ignore-this: 887697b6fd6226008d84422cfe33aa92

darcs-hash:20140910184310-fae1a-f57c2a44e5c2af15a98ad85229c507570493016a
add a lot of syntax checks to the CSS rule adding function

Ignore-this: b9ef00a14233039d94b42af4e7390c18

darcs-hash:20140912050336-fae1a-a4567cd6f9b8ec2ead03536b2e3e1ef77383808c
add another syntax check

Ignore-this: c6df0bde10fdcaca7cd94cc2b0e211e7

darcs-hash:20140912183609-fae1a-549db7f7a5b3ba3550558a3cd24d3d301d44a261
simplify the colour evaluation, we can now assume that the format is right

Ignore-this: 4ccdabbd9a2f735e01d82891eb439128

darcs-hash:20140912183952-fae1a-ca73a7dc1db668a63a9d8ecb4c2b96db164e7115
fix schadow string verification, spaces between values are not required

Ignore-this: 1fd42936b2ea93d8e41501701d86d63b

darcs-hash:20140913182807-fae1a-be5d6f3c7acf9690df1317bdd78be54d355487f3
the width of a columns needs to be evaluated as a size

Ignore-this: 358deb51900a069745a8ae2d6725f0b9

darcs-hash:20140913183049-fae1a-9377db7fd887a68a5b6fefb19658490858d71161