obsValueField.tag has an invalid jstl expression

Any page that utilizes obsValueField.tag will lead to an error like the following when run in Tomcat 7:

javax.servlet.jsp.JspException: org.apache.jasper.JasperException: /WEB-INF/tags/obsValueField.tag (line: 43, column: 2) "${c.datatype.boolean}" contains invalid expression(s): javax.el.ELException: Failed to parse the expression [${c.datatype.boolean}]

This is due to the fact that "boolean" is not a valid Java identifier and the JSTL parser is stricter about this in Tomcat 7. This should be a simple fix from:

${c.datatype.boolean}

to

${c.datatype['boolean']}