Fixed Major error, minor warnings

# Error
Gem::Installer::ExtensionBuildError: ERROR: Failed to build gem native extension.

    /usr/local/rvm/rubies/ruby-2.0.0-p0/bin/ruby extconf.rb 
checking for TA_Initialize() in -lta_lib... no
creating Makefile

make
compiling talib.c
talib.c: Na função ‘FLT2DBL’:
talib.c:107:6: erro: expected ‘(’ before ‘!’ token
talib.c:107:6: aviso: statement with no effect [-Wunused-value]
talib.c:107:22: erro: expected ‘;’ before ‘return’
make: ** [talib.o] Erro 1

# Annoying warnings

09:27:14 marco@macubuntu:~/desenv/talib-ruby/ext/talib (git:master+*:8e8fe09)  ruby-1.9.3-p392 
$ make
compiling talib.c
talib.c: Na função ‘ta_func_setup_in_real’:
talib.c:305:2: aviso: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
talib.c: Na função ‘ta_func_setup_in_price’:
talib.c:317:5: aviso: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
talib.c: Na função ‘ta_func_setup_out_real’:
talib.c:378:5: aviso: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
talib.c: Na função ‘ta_func_setup_out_integer’:
talib.c:396:5: aviso: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
talib.c: Na função ‘ta_func_setup_out_real’:
talib.c:384:1: aviso: control reaches end of non-void function [-Wreturn-type]
talib.c: Na função ‘ta_func_setup_out_integer’:
talib.c:402:1: aviso: control reaches end of non-void function [-Wreturn-type]
talib.c: Na função ‘ta_func_setup_opt_in_real’:
talib.c:361:1: aviso: control reaches end of non-void function [-Wreturn-type]
talib.c: Na função ‘ta_func_setup_opt_in_integer’:
talib.c:345:1: aviso: control reaches end of non-void function [-Wreturn-type]
talib.c: Na função ‘ta_func_setup_in_price’:
talib.c:330:1: aviso: control reaches end of non-void function [-Wreturn-type]
talib.c: Na função ‘ta_func_setup_in_real’:
talib.c:310:1: aviso: control reaches end of non-void function [-Wreturn-type]
talib.c: Na função ‘ta_func_setup_in_integer’:
talib.c:292:1: aviso: control reaches end of non-void function [-Wreturn-type]
linking shared-object talib.so