beremiz

file isExecutable
add custom TextCtrl allowed to enter long integer with bounds checking

It's needed because wx.SpinCtrl supports only 'int' type. For UDINT
and (U)LINT long type is necessary.
<xsd:attribute name="Compiler" type="xsd:string" use="optional" default="gcc"/>
<xsd:attribute name="CFLAGS" type="xsd:string" use="optional" default=""/>
<xsd:attribute name="Linker" type="xsd:string" use="optional" default="gcc"/>
<xsd:attribute name="LDFLAGS" type="xsd:string" use="optional" default=""/>