Allow watch format specifiers a la Visual Studio

Visual Studio allows to specify the watch format by appending ,n to the variable name.

E.g. foo,x is displayed hexadecimal, bar,s is displayed as string (char array)

An overview is available here (mostly printf-compatible):

http://msdn.microsoft.com/en-us/library/75w45ekt.aspx

PS: Also note the "pointer as array specifier" that allows to specify the number of elements displayed: pBuffer,[32]