* changes:
[apps] In i18n, syntax error
[escher] In text field, change background color when editing
[poincare] Pop up a syntax error for function with the wrong number of arguments
[apps/sequence][apps/graph] Define x/n only in list controllers
[apps/shared] Fix bug: avoid typing sum(cos(x),2,3) instead of sum(cos(n),2,3)
[apps/shared] Fix bug in goto
[apps/shared] Do not reset the textfield is the data has not been updated (syntax, math error)