Add features to default.properties FILE_TRANSFER_WARNING_SIZE and FILE_TRANSFER_MAXIMUM_SIZE

Specify a size on which Users will get a

warning of a possibly too big file

10MB = 10485760

100MB = 104857600

1GB = 1073741824

default = -1 (infinity)

maximum is 9223372036854775806 byte = 8388608TB
FILE_TRANSFER_WARNING_SIZE = -1

Specify the Maximum file size to be permitted to send

10MB = 10485760

100MB = 104857600

1GB = 1073741824

default = -1 (infinity)

maximum is 9223372036854775806 byte = 8388608TB
FILE_TRANSFER_MAXIMUM_SIZE = -1