Add testsuite for flags

[Maijin]

• fc [name] [color] set color for given flag
• fn list flags displaying the real name (demangled)
• fR [f] [t] [m] relocate all flags matching f&~m 'f'rom, 't'o, 'm'ask
• fx[d] show hexdump (or disasm) of flag:flagsize
• Usage: f [?] [flagname] # Manage offset-name flags
• f list flags (will only list flags from selected flagspaces)
• f. [[]] list local per-function flags (*) as r2 commands
• f.blah=$$+12 set local function label named 'blah'
• f* list flags in r commands
• f name 12 @ 33 set flag 'name' with length 12 at offset 33
• f name = 33 alias for 'f name @ 33' or 'f name 1 33'
• f name 12 33 [cmt] same as above + optional comment
• f-.blah@fcn.foo delete local label from function at current seek (also f.-)
• f-- delete all flags and flagspaces (deinit)
• f+name 12 @ 33 like above but creates new one if doesnt exist
• f-name remove flag 'name'
• f-@addr remove flag at address expression
• f. fname list all local labels for the given function
• fa [name] [alias] alias a flag to evaluate an expression
• fb [addr] set base address for new flags
• fb [addr] [flag*] move flags matching 'flag' to relative addr
• fC [name] [cmt] set comment for given flag
• fd addr return flag+delta
• fe- resets the enumerator counter
• fe [name] create flag name.#num# enumerated flag. See fe?
• fg bring visual mode to foreground
• fj list flags in JSON format
• fl [flagname] show flag length (size)
• fm addr move flag at current offset to new address
• fo show fortunes
• fr [old] [[new]] rename flag (if no new flag current seek one is used)
• fs ?+-* manage flagspaces
• fS[on] sort flags by offset or name