Parser for XML names is too lenient

[k0ral]

Follow-up of #187 .

The parseIdent/parseName functions are supposed to match the Name XML specification:

[4]   	NameStartChar	   ::=   	":" | [A-Z] | "_" | [a-z] | [#xC0-#xD6] | [#xD8-#xF6] | [#xF8-#x2FF] | [#x370-#x37D] | [#x37F-#x1FFF] | [#x200C-#x200D] | [#x2070-#x218F] | [#x2C00-#x2FEF] | [#x3001-#xD7FF] | [#xF900-#xFDCF] | [#xFDF0-#xFFFD] | [#x10000-#xEFFFF]
[4a]   	NameChar	   ::=   	NameStartChar | "-" | "." | [0-9] | #xB7 | [#x0300-#x036F] | [#x203F-#x2040]
[5]   	Name	           ::=   	NameStartChar (NameChar)*

This specification allows for a very limited set of characters, yet the current implementation of parseIdent is much more permissive. This issue is about aligning the implementation with the XML specification.