nexml export: NEXUS-specific curly braces in matrix

[ghost]

This is the ambiguity code in NEXUS. It should result in an uncertain state set in NeXML, not the use of the NEXUS syntax in a seq element.
See
http://treebase.org/treebase-web/search/downloadAStudy.html?id=10081&format=nexml
affected IDs:
S10081 S10108 S10135 S10146 S10350 S10466 S1050 S10553 S10667 S10671 S10676 S1070 S1094 S110 S1116 S1121 S1125 S11330 S11387 S1148 S11610 S11700 S11965 S11976 S1198 S12033 S12447 S12642 S12832 S12850 S12851 S12929 S12976 S12978 S12979 S12980 S12982 S12984 S12990 S12992 S12997 S12999 S13000 S13001 S13008 S13009 S13010 S13012 S13015 S13016 S13017 S13021 S13022 S13026 S13030 S13040 S13041 S13043 S13044 S13048 S13055 S13059 S13060 S13061 S13062 S13064 S13069 S13070 S13071 S13076 S13077 S13078 S13079 S13080 S13086 S13091 S13094 S13097 S13102 S13103 S13104 S13105 S13113 S13115 S13116 S13117 S13120 S13121 S13122 S13123 S13124 S13125 S13126 S13127 S13130 S13131 S13134 S13139 S13140 S13141 S13142 S13145 S13146 S13147 S13148 S13150 S13151 S13153 S13156 S13163 S13165 S13166 S13168 S13173 S13174 S13178 S13180 S13194 S13201 S13204 S13209 S13213 S13219 S13220 S13221 S13222 S13224 S13225 S13229 S13230 S13236 S13237 S13244 S13245 S1330 S13316 S13373 S13433 S1394 S1436 S145 S146 S1504 S1518 S1539 S156 S1585 S1601 S1688 S168 S1801 S1975 S2032 S2091 S2132 S2179 S225 S232 S2344 S255 S269 S270 S287 S295 S305 S334 S337 S341 S355 S356 S368 S384 S392 S396 S397 S409 S606 S615 S700 S733 S838 S874 S920 S991 S9941 S9944 S997

Reported by: mholder