ExprTreeBuildTree() function

Parse the subexpression at builder->token and return with the node on the stack. builder->token is advanced to the next unconsumed token. Returns JIM_OK if OK or JIM_ERR on error and leaves a message in the interpreter result. 'precedence' is the precedence of the current operator. Tokens are consumed until an operator with an equal or lower precedence is reached (or strictly lower if right associative). If EXPR_UNTIL_CLOSE is set, the subexpression extends up to and including the next close parenthesis. If EXPR_FUNC_ARGS is set, multiple subexpressions (terms) are expected separated by comma If EXPR_TERNARY is set, two subexpressions (terms) are expected separated by colon 'exp_numterms' indicates how many terms are expected. Normally this is 1, but may be more for EXPR_FUNC_ARGS and EXPR_TERNARY.