Add value to store price type extrafield without currency in ODT
Extrafields on ODT (propal) : fix value of price with currency & display date with correct format
New function to fill ODT substitution array with extrafield of object
Use price2num() function instead of price() to use calcul in ODT.
Libre/Open Office wants number with dot and no space to allow make calcul in ODT document
Merge branch 'extrafields' into fgd

Conflicts:
	htdocs/core/class/commondocgenerator.class.php