lexer Python: support continue \ in strings
lexer Python: support continue \ in strings

vhanla/CudaText,Alexey-T/CudaText,Alexey-T/CudaText,vhanla/CudaText,Alexey-T/CudaText,vhanla/CudaText,vhanla/CudaText,Alexey-T/CudaText,Alexey-T/CudaText,vhanla/CudaText,Alexey-T/CudaText,Alexey-T/CudaText,vhanla/CudaText,vhanla/CudaText,vhanla/CudaText,Alexey-T/CudaText,vhanla/CudaText,vhanla/CudaText